Autonomic dysreflexia, overheating, profuse or absent sweating, orthostatic hypotension, bradycardia, neurogenic bowel, neurogenic bladder, sexual function.

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Most people think of the nervous system in terms of what they can feel and control: moving an arm, walking, sensing pain, or noticing a touch.

But much of the nervous system’s most important work happens quietly, continuously, and without conscious instruction.

Normally, your heart adjusts its rate when you stand up. Blood vessels tighten or relax to help maintain blood pressure. Your pupils change size in different light. Your stomach and intestines coordinate digestion. Your bladder fills, signals the brain, and—when timing and circumstances allow—empties. When you become overheated, your body shifts blood toward the skin and activates sweating to release heat.

You do not have to stop and direct any of these processes.

They are managed through a remarkable communication network called the autonomic nervous system, or ANS.

For people living with spinal cord injury, this system matters enormously. A spinal cord injury can affect far more than strength, sensation, and mobility. It can change how the body regulates blood pressure, heart rate, temperature, sweating, bowel and bladder function, sexual function, and circulation.

Understanding the autonomic nervous system gives us a practical foundation for all of those topics.

This article is the map. In future articles, we will use that map to explore sweating, heat intolerance, thermal regulation, autonomic dysreflexia, and the language clinicians use when describing a spinal cord injury.

The Nervous System Beyond Movement

The autonomic nervous system helps regulate the body’s internal environment. It works in close partnership with the brain, spinal cord, peripheral nerves, blood vessels, organs, glands, and skin.

Its goal is homeostasis: keeping the internal environment stable while the outside world, and the demands on your body, keep changing.

That does not mean the body stays perfectly unchanged.

It means the body is constantly making adjustments.

When you exercise, your heart needs to pump more blood. When you sit up in a wheelchair, blood momentarily shifts toward your legs, and your circulation must respond to keep blood flowing to your brain. When the weather is hot, your body must release heat. When you eat, your digestive system needs to become more active. When you are frightened, in pain, dehydrated, fighting an infection, or suddenly exposed to cold, the body must adapt.

The autonomic nervous system helps coordinate those responses.

It influences:

• Heart rate and the force of heart contraction

• Blood pressure and blood-vessel tone

• Sweating and temperature regulation

• Skin blood flow

• Digestion and intestinal movement

• Bladder storage and emptying

• Bowel function

• Pupil size

• Sexual function

• Certain glandular and metabolic responses

“Autonomic” is often translated as “automatic,” and that is helpful—as long as we do not take it too literally. These functions are largely outside conscious moment-to-moment control, but they are not separate from the rest of life. Emotion, pain, stress, sleep, exercise, hydration, illness, medications, environment, and spinal cord injury can all influence autonomic function.

A Quick Map of the Spine

Before talking about autonomic pathways, it helps to understand the language used to describe locations in the spine.

Clinicians describe different parts of the spine and spinal cord by region and level.

The adult vertebral column has 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, 5 fused sacral vertebrae, and usually 4 fused coccygeal vertebrae. The spinal cord is also organized into regions and segments, but the bony level seen on an X-ray or MRI is not always exactly the same as the neurologic level of the spinal cord.

That distinction can become important after spinal cord injury.

A person may hear an injury described as “at T6.” Depending on the situation, that could mean the location of a vertebral fracture, a level seen on imaging, a surgical description, or the person’s neurologic level of spinal cord injury. Those terms are related, but they are not always interchangeable.

For now, the important idea is simple: the spinal cord is organized in levels, and those levels help us understand which signals can travel between the brain and different parts of the body.

The ANS Has Three Divisions

The autonomic nervous system is usually described as having three interconnected divisions:

The sympathetic nervous system

The parasympathetic nervous system

The enteric nervous system

The first two receive most of the attention because they help explain many changes seen after spinal cord injury. The third—the enteric nervous system—is especially important for digestion and bowel function.

These systems are not simply “on” or “off.” They are continuously active, responding to the body’s needs and balancing one another in organ-specific ways.

A helpful starting point is a story.

Imagine you are walking at dusk and a tiger steps out of the trees. You do not have time to think through a plan.

The sympathetic system would slam into action. Your heart rate would rise. Your blood pressure would climb. Blood vessels in the skin and gut would tighten so more blood could be sent toward the heart and working muscle. Your pupils would dilate so you could take in more light, especially in the dark. Digestion would be pushed aside.

In that moment, the body is not trying to rest, eat, or recover.

It is trying to survive.

Now imagine the opposite scene: the danger has passed, the meal is over, and the body can settle. That is closer to the parasympathetic system. It supports restoration, digestion, elimination, and other routine internal functions. It is not laziness. It is recovery and maintenance.

Then there is the enteric system, which coordinates much of the gastrointestinal tract’s local activity. This network is so locally smart that parts of bowel function can still work even when the brain is no longer in the conversation.

That is one reason a bowel program can succeed after spinal cord injury. Digital stimulation or a suppository can trigger a local response in the rectum and lower bowel, even without a reliable connection to the brain. The gut is not waiting for a conscious command. It can still be trained through routine, timing, and the right stimulus.

The real physiology is more nuanced than “fight or flight” versus “rest and digest.” Both sympathetic and parasympathetic activity are essential for normal health. The tiger story is a way to remember the contrast, not a claim that the sympathetic system only turns on in emergencies.

The Sympathetic System: Thoracolumbar Outflow

The sympathetic nervous system is active every day.

It helps maintain blood pressure when you sit up. It adjusts the circulation during exercise. It participates in blood-vessel control, heart-rate regulation, energy use, skin blood flow, and sweating. It becomes especially important when the body is responding to heat, cold, pain, fear, blood loss, illness, dehydration, or a sudden drop in blood pressure.

The sympathetic system is called thoracolumbar because its primary spinal cord outflow begins in the thoracic and upper lumbar portions of the spinal cord—classically from T1 through L2.

That means the middle and lower portions of the spinal cord are not simply pathways for leg movement or sensation. They also contain important autonomic nerve cells and connections that influence organs and blood vessels throughout the body.

In broad terms, sympathetic activity can:

• Increase heart rate and the force of heart contraction

• Change the diameter of blood vessels

• Redirect blood flow according to the body’s needs

• Help maintain blood pressure

• Mobilize energy during physical or physiologic stress

• Influence skin blood flow

• Activate sweating

Sweating deserves special attention because it is often misunderstood.

Sweat glands are controlled through the sympathetic nervous system. That fact may seem surprising because people often associate sweating with heat, exercise, or anxiety—not with sympathetic anatomy.

But sweating is one of the body’s major tools for releasing heat. It is not just a skin-level event. It requires communication among the brain, spinal cord, sympathetic pathways, peripheral nerves, sweat glands, blood vessels, the skin, and the surrounding environment.

We will return to this in a future article, because after spinal cord injury that communication can be altered in ways that affect heat tolerance, sweating patterns, exercise safety, and daily comfort.

The Parasympathetic System: Craniosacral Outflow

The parasympathetic nervous system is often summarized as “rest and digest.” That is a useful entry point, but it is more accurate to think of it as a system that supports restoration, digestion, elimination, and organ-specific regulation.

Unlike the sympathetic system, the parasympathetic system does not arise from the cervical or thoracic spinal cord.

It is called craniosacral because it comes from two locations:

• The brainstem, where parasympathetic fibers travel with certain cranial nerves

• The sacral spinal cord, especially the S2–S4 segments

The cranial portion includes pathways that influence structures in the head as well as organs in the chest and abdomen. The vagus nerve is the best-known example. It carries parasympathetic signals to many organs, including the heart, lungs, and much of the digestive tract.

The sacral portion is particularly important in spinal cord medicine. Parasympathetic pathways from S2–S4 contribute to lower urinary tract function, distal bowel function, and aspects of sexual function.

In broad terms, parasympathetic activity can support:

• Slowing of the heart under certain conditions

• Digestion and intestinal activity

• Bladder emptying

• Bowel activity

• Sexual arousal-related responses

• Organ-specific restoration and maintenance functions

One important detail: the sympathetic and parasympathetic systems often influence the same organ, but not always in simple opposition.

The heart is a familiar example. Sympathetic input can increase heart rate and force of contraction, while parasympathetic input can slow heart rate. Other organs have more complicated patterns. Some receive predominantly one type of autonomic input. Others respond differently depending on whether the body is resting, exercising, digesting, under stress, or adapting to heat.

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The Enteric Nervous System: The Gut’s Local Network

There is a third division of the autonomic nervous system called the enteric nervous system.

This is a large network of nerves embedded within the wall of the gastrointestinal tract. It helps coordinate movement of food through the intestines, secretion, absorption, and other digestive functions.

The enteric nervous system can handle many functions locally, which is why it is sometimes called the body’s “second brain.” But it is not isolated. It is influenced by signals from both the sympathetic and parasympathetic systems, as well as by diet, hydration, stress, activity level, medications, illness, and injury.

That local intelligence is one of the most practical facts in spinal cord medicine.

After SCI, the brain may no longer have a reliable connection to the bowel. The bowel, however, can still respond to local cues. That is why digital stimulation or a suppository can produce a bowel movement even when voluntary control is gone.

The response is not magic, and it is not a return of brain control.

It is the gut and lower spinal circuits doing work they were built to do.

A bowel program uses that biology. Timing, routine, diet, hydration, positioning, and a consistent stimulus can train the bowel to empty more predictably.

The system is smart.

It can also be trained.

For people with spinal cord injury, bowel function is often affected by changes in several of these systems at once. Understanding the autonomic nervous system helps explain why a bowel program is not simply about the intestines. It is also about nerves, reflexes, routine, positioning, diet, hydration, medications, and communication between the brain and body.

The Hypothalamus: A Coordinator of Internal Balance

At the base of the brain is a small but enormously influential structure called the hypothalamus.

You may hear the hypothalamus described as the body’s thermostat. That description is useful, but incomplete.

A household thermostat mainly turns a heating or cooling system on or off. The hypothalamus does something much more complex.

The hypothalamus plays an important role in regulating:

• Body temperature

• Sweating and skin blood flow

• Fluid balance and thirst

• Hunger and energy balance

• Sleep and circadian rhythm

• Stress responses

• Reproductive and hormonal functions

• Autonomic responses to internal and external demands

The hypothalamus is not “the parasympathetic system,” and it is not the only control center for autonomic function. It is better understood as a major coordinator within a broader network that includes the brainstem, spinal cord, peripheral autonomic nerves, and organs themselves.

This becomes especially relevant when we discuss temperature.

When body temperature rises, the response is not simply “turn on sweat.” Temperature signals must be detected, interpreted, and translated into coordinated changes in sweating, skin blood flow, circulation, thirst, behavior, and sometimes shivering or heat production.

After spinal cord injury, the pathways that carry some of those signals downward through the spinal cord may be interrupted. That can leave the body less able to sweat or adjust skin blood flow below the level of injury—even though the brain still recognizes that the body is too hot.

Why Spinal Cord Injury Changes More Than Movement

A spinal cord injury can interrupt communication between the brain and the autonomic circuits below the injury.

This does not mean that every autonomic function disappears. The body still has local reflexes, peripheral nerves, organs, glands, and portions of the spinal cord that remain active. But coordination between the brain and body can change dramatically.

That is why a spinal cord injury may affect:

• Blood-pressure regulation

• Heart-rate responses

• Sweating

• Temperature control

• Skin circulation

• Bladder storage and emptying

• Bowel function

• Sexual function

• Responses to pain or irritation below the level of injury

The specific effects vary widely. They depend on the level of injury, whether the injury is complete or incomplete, how much time has passed since injury, medications, medical conditions, environment, and the particular body system being discussed.

This is also why spinal cord injury is not just a condition of paralysis.

Mobility and sensation are highly visible parts of SCI. Autonomic changes may be less visible, but they can be just as important to health, comfort, independence, safety, and quality of life.

A Simple Example: Getting Too Hot

Imagine being outside on a hot day.

As your body temperature rises, temperature sensors in the skin and deeper tissues send information to the brain. The hypothalamus and other autonomic centers help coordinate a response. Signals travel down through the brainstem and spinal cord, activating sympathetic pathways that influence sweat glands and blood vessels in the skin.

Sweat reaches the skin surface. As it evaporates, it helps remove heat from the body. Blood flow to the skin may increase, allowing the body to release more heat to the environment. Meanwhile, the heart and circulation must adapt to support both physical activity and heat loss.

It is a complex response, happening in seconds to minutes, without requiring conscious direction.

After a spinal cord injury, a person may still recognize that they feel hot. But if descending autonomic signals cannot effectively reach the parts of the body below the injury, sweating and skin blood-flow responses may be reduced, absent, altered, or redistributed.

That is why heat after spinal cord injury is not simply a matter of comfort.

It can become a safety issue.

Looking Ahead

The autonomic nervous system is a hidden control network, but it is not an abstract topic. It affects everyday life: standing up, eating, using the bathroom, sleeping, exercising, being outdoors, staying cool, and responding to illness or stress.

For those living with spinal cord injury, this system helps explain why the body may respond differently after injury—even when a problem is not visible from the outside.

In upcoming articles, I will build on this foundation by discussing:

• How sweating and body-temperature regulation work

• Why heat exposure can be more complicated after SCI

• The hypothalamus, spinal cord, and sympathetic pathways involved in thermal control

• Why injuries at different levels can lead to different autonomic effects

• The ASIA examination and what clinicians mean by “neurologic level of injury”

• Autonomic dysreflexia, including why it is especially important for many people with injuries at or above T6

The more we understand the body’s hidden control systems, the better we can recognize symptoms, prevent complications, ask informed questions, and build strategies for living well after spinal cord injury.

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Disclaimer:

How I use AI: I use AI the way I once used human editors—to help with grammar, structure, and clarity. The ideas, clinical judgments, and stories are mine, drawn from 36 years of living with a spinal cord injury and 25 years in physical medicine and rehabilitation and spinal cord medicine. I write the content first, then use AI to tighten the language and improve flow, and I personally review and edit every piece before it is published. AI does not decide what I believe, what I recommend, or what I share; it just helps me say it more clearly and consistently. Frankly, it allows me to publish. I would not feel comfortable enough to publish without it.

What this is (and isn’t): This newsletter is for education and reflection, not personal medical advice, diagnosis, or treatment. It cannot replace an individual evaluation or relationship with your own clinician, and you should never delay or ignore professional medical advice because of something you read here.

Heat can quietly kill someone with spinal cord injury.
Not just make them miserable.
Kill them.

That sounds extreme, but it’s true.

In this article, I want to talk about summer heat, and why hot environments plus spinal cord injury are not just uncomfortable, but medically dangerous and, in some situations, life-threatening.

Winter Rehabilitation, Summer Reality

My spinal cord injury happened in January, on a mountain, in the cold.

The spinal cord injury rehabilitation program at the University of Utah was excellent, and the education was life-changing. The therapy, teaching about bowel and bladder, skin care, and autonomic dysreflexia, all of it was top-notch and helped me transition from inpatient rehab to a month of outpatient therapy, and then back to college while still aiming for medical school.

But it was all happening in winter. There was snow outside, frozen sidewalks, and cold air.

I do not remember anyone telling me in clear, memorable language:

Maybe it was mentioned. If it was, it did not stick because the whole world outside the rehab hospital was frozen.

Summer in Texas: My Unintentional Heat Experiment

Fast-forward a few months.

Texas summer.

Brutal heat, brutal humidity.

I had a new wheelchair-accessible van, which was supposed to be my step toward freedom and independence. The problem was that the air-conditioning system did not actually work, and I did not know it.

I was told by the dealership, “big vans just take a long time to cool off,” so I believed it.

Day after day, I climbed into that oven on wheels after it had been sitting on black asphalt in the Texas sun, breathing dense humid air, and waiting for an AC system that was never going to cool anything. For weeks, I was essentially living inside a heat-stress experiment, except it was accidental, and nobody had warned me how dangerous the combination of heat, humidity, and spinal cord injury could be.

Eventually, someone checked the system and discovered the real problem: the air- conditioning was never working from the start. Once it was repaired, the van finally started to cool the way it should have from day one.

By that point, however, I had already learned something important the hard way: in my body, with my spinal cord injury, heat meant trouble.

Serious trouble.

What Overheating Actually Felt Like

I learned a crucial lesson: I overheat quickly, but with a delayed warning.

That delay was the tricky part. An overwhelming wave of fatigue, physical and cognitive, would show up 30 to 60 minutes after the exposure.

You go outside for a while and feel “okay enough,” with a vague sense that something is not right.
You finish what you are doing.
You roll inside, thinking that you are now safe.

And then the crash comes.

I would feel like every muscle in my body was weak, including the muscles below the lesion that I cannot move. It felt like I had just run a marathon that my legs never actually ran.

The fatigue was overwhelming. Brain fog was profound. I did not have the energy to think clearly, could not read, and barely wanted to speak.

My preferred position at that point was:

• Recliner or couch

• Cold water on my face and neck

• Ice water to drink

• Staring at the ceiling or TV

That was not simply “being a little hot.”
That was systemic collapse.

And it happened again and again.

Over time, I noticed a pattern.

There seemed to be a threshold, a “safe temperature” zone.

For me, that was around 82°F, which is about 27.8°C. Below that, I could be outside for long periods with much less risk of overheating. The higher the temperature, the shorter the time I could remain outside.

It did not feel like a gentle slope; it felt more like a cliff.

I could function reasonably well at the moment, but 30 minutes after coming inside from an excessively hot environment, I was wrecked.

The most difficult part was the lag. Even if I was paying attention to the temperature and the clock, the worst effects were often already building before I fully appreciated them.

Real life is real life. People still want to fish, go out on boats, attend outdoor events, and spend time with family and friends. Not every decision can be made as if you are living inside a laboratory.

There has to be some balance.

But if I stay out long enough that I already feel bad while I am still in the heat, I know what is coming next. It will get worse.

Therefore, people with SCI must know their limits.

Residency, Poikilothermia, and a Deliberate Experiment

Years later, during my residency, I came across a paper on poikilothermia in tetraplegia.

Poikilothermia is the tendency of the body’s core temperature to drift toward the ambient temperature when thermoregulatory defenses are impaired. The term comes from poikilotherms, such as lizards, which take on the temperature of their surroundings.

Reading that paper, I realized:

“This explains what I went through back in Texas.”

By this time, the air conditioning in the van was working properly. I was no longer being cooked by accident.

However, I did what residents and scientists sometimes do: I decided to test the concept on myself deliberately, as an experiment.

I wanted to know how fast my temperature would rise in a hot, closed environment, now that I understood poikilothermia and had already experienced months of unintentional overheating.

Lunch in the Van: Self‑Experimentation (DO NOT TRY THIS!)

During one of my August rotations as a resident, I converted my van into a controlled heat chamber.

At lunch, I would go out to the van, park on dark asphalt in the Houston summer, turn off the AC, close the doors, take a baseline temperature, and eat my sandwich while recording repeated measurements.

My core temperature rose rapidly, faster than I had anticipated. Twenty-five years later, I no longer have the data points, but I still remember the patterns.

Inside the van, I did not feel as bad as the numbers suggested. I felt functional enough to eat, collect data, and convince myself that this was scientifically interesting.

The collapse still waited for me inside the hospital.

By the time lunch was over and I struggled to roll back into the building, I was an absolute disaster, barely able to push myself down the flat hallways, foggy, exhausted, and practically nonfunctional.

My attending noticed something was wrong and asked, “What are you doing at lunch?”

I held up my data and said something like, “I think I’ve discovered something about myself.”

He gasped and told me I had to stop. This would not be good press for the residency program if I died in the van with data points next to me.

That ended my self-experimentation.

Between the unintentional overheating when the van’s refrigerant was not working and the later intentional experiment with a fully functioning van, I observed my physiology under heat stress from both angles.

The lesson was unmistakable: heat plus spinal cord injury is not just uncomfortable. This can be dangerous.

How Heat Regulation Changes After SCI

The key point is that spinal cord injury can disable the body’s normal equipment for getting rid of heat.

Maintaining a core body temperature within a narrow range is essential for the brain, heart, spinal cord, and other vital organs.

In an intact nervous system, the hypothalamus maintains temperature using two major mechanisms:

• Skin blood flow, which helps dissipate heat

• Sweating, which cools the body through evaporation

Both rely on the descending sympathetic pathways that travel through the spinal cord.

Both are disrupted in high-level SCI.

Cutaneous vasodilation is not simply a passive loss of vascular tone. This requires an active command from the hypothalamus. In tetraplegia and high thoracic injuries, these commands do not reach the spinal sympathetic neurons below the level of injury.

As a result:

• Large regions of skin cannot undergo the vasodilation needed to carry heat to the surface

• Sweat glands below the lesion never receive the signal to turn on

You are left with a large body surface area that cannot meaningfully participate in heat reduction, while you continue to generate heat internally through daily activities, transfers, pushing a chair, or simply sitting in a hot environment.

Imagine driving a car without a radiator.
The car can still run and build heat.
You cannot get rid of the heat.
You overheat.

How Dangerous Can This Get?

The dangerous part is that the warning signs are often blunted.

Individuals with high cervical or upper thoracic SCI can develop significant hyperthermia under passive heat stress, with core temperatures exceeding 100.4 to 102.0 Fahrenheit, or 38 to 39°C, while reporting surprisingly mild discomfort. In addition, there are published cases of higher temperatures leading to death due to spinal cord injury from excessive, prolonged environmental heat exposure.

This is not an infection-related fever and will not respond to acetaminophen or ibuprofen.

The body is retaining heat because it has lost the ability to effectively get rid of it.

In individuals with tetraplegia or high-level paraplegia, poikilothermia and environmental hyperthermia can predispose them to life-threatening heat complications, including multi-organ failure and cardiorespiratory arrest.

That is the life-threatening potential I want readers to understand when they think about summer and spinal cord injury.

Who Needs to Treat Summer Like a Medical Risk?

The risk is not uniform across all injuries.

It is greatest when:

• The level is high, especially cervical or upper thoracic injury above T6

• The injury is complete rather than incomplete

• Ambient temperatures and humidity are high

• Cooling options are limited, such as no AC, enclosed spaces, or direct sun

This is a very important concept: overheating can happen with very high heat in a short period, but also with lower heat or moderate heat if the exposure lasts long enough.

How I Now Build My Summers Around Heat

In response to all of this, I began building my summers around heat.

I check the forecast as a routine part of planning.
I know my personal limit temperature, approximately 82°F, or 27.8°C.
I decide whether an activity is for the morning, evening, or not at all.

Boats.
Football games.
Outdoor family events.

I still go, but with rules:

• Favor morning or evening over midday

• Seek shade and airflow

• Bring water and spray bottles for my face and neck

• Assume that the worst effects are building up and lagging behind my current appreciation of the situation

I have accepted that my autonomic nervous system below the lesion is permanently out of the conversation.

Therefore, I must intentionally compensate for it and plan for it.

At the same time, this must be balanced with real life. People want to fish, go out on boats, or spend time outdoors with friends and family. You do not want to live as if every summer day is a hazard to avoid completely.

However, if you start to feel bad while you are still in the heat, you need to respect that warning. This situation is only going to get worse.

Know your limits, but live your life.

Stay safe. Stay cool.

- Glen House

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Disclaimer:

How I use AI: I use AI the way I once used human editors—to help with grammar, structure, and clarity. The ideas, clinical judgments, and stories are mine, drawn from 36 years of living with a spinal cord injury and 25 years in physical medicine and rehabilitation and spinal cord medicine. I write the content first, then use AI (PaperPal) to tighten the language and improve flow, and I personally review and edit every word before it is published. AI does not decide what I believe, what I recommend, or what I share; it just helps me say it more clearly and consistently. Frankly, it allows me to publish. I would not feel comfortable enough to publish without it.

What this is (and isn’t): This newsletter is for education and reflection, not personal medical advice, diagnosis, or treatment. It cannot replace an individual evaluation or relationship with your own clinician, and you should never delay or ignore professional medical advice because of something you read here.

I have been writing about the way spinal cord injury can rapidly change metabolism. After SCI, many people develop what looks very much like an accelerated insulin-resistant state. Over time, that can push people toward metabolic syndrome, prediabetes, and type 2 diabetes, especially when the food environment around them is the Standard American Diet (or the S.A.D. diet).

I have also shared how I have tried to protect my own health over the last decade. For me, that has meant a very low-carbohydrate approach (50 grams of total carbs or less per day), with a serious effort to eliminate sugar and refined carbohydrates as much as possible.

But I have also said I would eventually do something I almost never do.

I would eat a normal restaurant meal from my past and show you what happened.

Well, I did it.

And the results were about as bad as I expected.

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The Experiment I Did Not Really Want to Do

Last night, I went with my family to P.F. Chang’s. We used to go there often when we lived in Colorado, and even though it is now a longer drive from where I live, we decided to make it part of a family night out.

I ordered something I used to eat years ago: Chang’s Spicy Chicken.

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I did not eat rice with it. That is important. Rice alone can create a rapid glucose spike for me, so I wanted this to be about the entrée itself.

As I was eating it, I could tell immediately that it tasted sweet. That is one of the interesting things that happens when you eliminate sugar for a long time. Your palate changes. Sweetness becomes much more obvious.

And this tasted very sweet.

Watching the Spike Happen in Real Time

As you know, I am a strong advocate for using a continuous glucose monitor, or CGM, because it gives you real-time feedback. It lets you stop guessing about what food is doing to you.

I wear the FreeStyle Lingo, which does not require a prescription. Unlike some other CGMs, it does not give exact readings above 200 mg/dL. It simply tells you that you are above 200.

That is exactly what happened.

My glucose started rising like a rocket. During the entire hour drive home, I kept asking my daughter, who was watching my phone, to tell me the number.

It kept climbing.

Honestly, I had this strange feeling of being scammed by the restaurant. I know that sounds dramatic, but that is what it felt like. How can a savory chicken entrée do this to my blood sugar? Why is this not obvious on the menu? Why is sugar allowed to hide in a main course in a way that most people would never suspect?

It took about two hours before I started crossing back toward the safer 140 mg/dL range.

The Comparison Day

The next day, I returned to my usual low-carbohydrate approach.

That screenshot tells a very different story.

The Investigation

That P.F. Chang’s meal sent me down a rabbit hole.

I started looking at the nutrition data from popular restaurants, coffee shops, smoothie chains, and fast-food companies. I wanted to know how much sugar was sitting inside normal menu items that people order every day.

The numbers were worse than I expected.

In a previous newsletter, I introduced a simple tool I like to use called the Glazed Donut Index, or GDI. It is not a scientific index. It is a communication tool.

One Krispy Kreme Original Glazed Doughnut contains 10 grams of sugar, so I use that as the baseline for the GDI (Krispy Kreme nutrition PDF).

That means:

• 30 grams of sugar = 3.0 GDI

• 60 grams of sugar = 6.0 GDI

• 100 grams of sugar = 10.0 GDI

• 189 grams of sugar = 18.9 GDI

Yes, 189 grams is a real drink in the table below.

Is a donut the perfect metabolic comparison? Of course not. A sugary drink, a smoothie, a donut, and a sauced entrée all differ in fiber, fat, protein, fructose content, gastric emptying, food matrix, and how quickly they may hit the bloodstream.

In fact, a sugary drink may be worse than a donut for many people.

But that is not the point.

The point is that “55 grams of sugar” can feel abstract.

“Five and a half glazed donuts” does not.

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Why This Matters at Restaurants

We often think we are making a reasonable choice because we did not order dessert.

But dessert-level sugar can be sitting inside the meal.

P.F. Chang’s Teriyaki Chicken has 70 grams of sugar, which is the equivalent of 7 glazed donuts by the GDI. Chang’s Spicy Chicken, the meal I ate, has 62 grams of sugar, or 6.2 GDI, according to the P.F. Chang’s nutrition guide (P.F. Chang’s nutrition guide).

That is WITHOUT adding rice.

This is the problem. Sugar is added because it makes food taste better. It makes us say, “That was sooo good.” Americanized Chinese restaurants are especially known for sweet sauces, but this is not just a Chinese food problem.

It is everywhere.

Coffee drinks. Smoothies. Lemonades. Refreshers. Sauces. Salads. “Protein” drinks. “Antioxidant” smoothies. Plant-based options. Foods that sound healthy or harmless can still be loaded with sugar.

So I built the table below to make the point visible.

The Hidden Sugar Table

The tables below are sorted within each company from highest sugar to lowest. I kept the comparison simple: item, size, sugar grams, and GDI.

What Jumped Out at Me

First, liquid sugar is the repeat offender. Dunkin’, Jamba, Dutch Bros, Chick-fil-A, Starbucks, Wendy’s, and Panera all have drinks in this table that cross the 30-gram threshold. Some do not simply cross it. They blow past it.

Second, fruit does not automatically mean low sugar. A smoothie or juice can come from real ingredients and still deliver a very large sugar load. For someone with insulin resistance, liquid fruit may behave very differently than whole fruit eaten with a meal.

Third, savory does not mean safe. P.F. Chang’s is the clearest example here. A chicken entrée, beef entrée, or vegetable side can carry a sugar load that many people would never associate with dinner.

Fourth, the “healthy” promotion is powerful, but often misleading. Words like matcha, almond milk, refresher, protein, antioxidant, plant-based, or lemonade may describe something true about an item, but they do not erase the sugar number.

Why This Matters More After Spinal Cord Injury

Everyone should be aware of hidden sugar. But for people with spinal cord injury, the stakes are different.

I have previously described this as Paralysis Metabolic Dysfunction. It is the intersection of metabolic syndrome with the unique physiological changes that happen after spinal cord injury.

After SCI, many people experience changes in body composition, muscle mass, visceral fat, glucose handling, inflammation, and cardiometabolic risk. That does not mean every person with SCI should eat the same way. It does mean the standard food recommendations may be especially mismatched to the physiology many of us are living with.

In an 8-week randomized controlled trial of adults with chronic SCI and insulin resistance or prediabetes, a low-carbohydrate/high-protein dietary pattern was associated with reduced total body fat mass, reduced visceral fat mass, and improved lipid measures compared with habitual diet (Li, Gower, McLain, and Yarar-Fisher, 2022).

That is the kind of study I pay attention to because it points us toward the real target.

Not food ideology.

Metabolic function.

The Practical Takeaway

The message is not that you can never eat at a restaurant.

The message is that you should know what you are actually choosing.

Here are a few practical filters I use:

• If it is sweet and liquid, assume your sugar may spike.

• If it has a health halo word, still check the sugar.

• If it is sauced, glazed, teriyaki, sweet-and-sour, honey, or “crispy honey,” assume it may be sugar-loaded.

• If you use a CGM, test your own response. Your body is the study that matters most for you.

• If you live with SCI, remember that lower muscle mass and reduced muscle contraction can change glucose disposal.

Deep Dive

Total sugar versus added sugar

For this GDI table, I used total sugar because not every restaurant source reports added sugar in a consistent way. That is a limitation, but it also makes the comparison easier for readers.

Clinically, added sugar and total sugar are not identical. A smoothie may contain naturally occurring sugars from fruit, while a soda may contain mostly added sugar. But from a glucose-load standpoint, the total amount still matters, especially when it is delivered quickly in liquid form.

The SCI metabolic context

The SCI metabolism conversation is not simply about willpower. It is about altered physiology.

Paralyzed or underused muscle does not function like normally contracting muscle. Lower active muscle mass can reduce glucose disposal. Visceral adiposity and inflammation can worsen insulin resistance. Autonomic and gut changes may alter energy balance and metabolic signaling.

This is why I keep coming back to the same theme: people with SCI deserve metabolic strategies built for SCI physiology, not generic advice copied and pasted from the able-bodied population.

Why the GDI works

Sugar grams are easy to ignore because they are abstract.

GDI makes the number visual.

It converts “90 grams of sugar” into “nine glazed donuts.”

That image is sticky, and sticky images change behavior.

Sometimes that is exactly what people need first.

The Menu Label I Wish Existed

Can you imagine how our diets might change if every restaurant had to list the Glazed Donut Index next to each menu item?

Not just calories.

Not just a tiny nutrition PDF buried somewhere online.

A visible number on the menu.

Chang’s Spicy Chicken: 6.2 GDI.

Chocolate Milkshake: 9.0 GDI.

OREO Coolatta: 18.9 GDI.

That would change behavior quickly. It would also make it harder for companies to hide dessert-level sugar inside drinks, sauces, and meals that are not presented as dessert.

Closing

Hidden sugar is not hidden because the data does not exist.

It is hidden because sweetness sells. It tastes good. It keeps us coming back for more.

In too many cases, it feels like profits over health.

Once you see the GDI, you cannot unsee it.

And for those of us living with spinal cord injury, seeing it clearly may be one more step toward building the best possible metabolic situation for the body we actually live in.

Be curious like your health depends on it—because it does.
Test your own response.
Don’t outsource your metabolism to a menu.

Source Notes

• The GDI baseline uses 10 grams of sugar for one Krispy Kreme Original Glazed Doughnut, from the Krispy Kreme nutrition PDF.

• Restaurant nutrition values were taken from official nutrition pages or PDFs listed in each company section.

Glen House, MD

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Are they different diagnoses? Did the medical world change its mind? Is this being politically correct? Why do some people say “quad” while others say “tetra”? Which is correct, and what should we say?

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As a physician involved in spinal cord injury care, I want to explain this topic in a clear and practical manner.

Am I a:

• quadriplegic physician?

• tetraplegic physician?

• physician with quadriplegia or tetraplegia?

All good questions.

My preference: First, I personally do not care. In reality, I use both terms depending on the audience and their familiarity with the term tetraplegia. Clinically, I use tetraplegia, and when speaking with individuals who have had paralysis for a long time, most still use quadriplegia, and so do I.

However, focusing on the person first and the condition second makes more sense and seems more appropriate. For example, I am not a quadriplegic or tetraplegic physician. I am a physician with quadriplegia/tetraplegia. For example, a “person with diabetes” is preferred over a “diabetic person.”

The Short Answer: They Mean the “Same Thing”

Both “quadriplegia” and “tetraplegia” describe “paralysis that involves all four limbs”

• Both arms (or at least some involvement of the upper extremities, could be as minimal as finger strength, as seen in a C8 tetraplegic)

• Both legs

This occurs after an injury to the cervical (neck) portion of the spinal cord.

Therefore, if someone says they are “quadriplegic” or “tetraplegic,” they are talking about the same general pattern of paralysis. The difference is not in their bodies; it’s in the word.

Why Are There Two Words?

The history here is mostly about “language,” not medicine.

• Quadri‑ comes from Latin and means “four.”

• Tetra‑ comes from Greek and also means “four.”

“‑plegia” comes from Greek and means “paralysis.”

So:

Quadriplegia = Latin (“quadri‑”) + Greek (“‑plegia”)

Tetraplegia = Greek (“tetra‑”) + Greek (“‑plegia”)

In other words, “quadriplegia” is a mixed Greek‑Latin word, while “tetraplegia” is a pure Greek word and matches other terms we already use, like “paraplegia” (also Greek‑Greek).

Language purists – and eventually the spinal cord injury community that develops classification standards – wanted the terminology to be consistent, so they favored “tetraplegia.”

How the Shift to “Tetraplegia” Happened

For many years, especially in North America, “quadriplegia” was the dominant term in everyday language and even in a lot of medical writing.

In contrast, “tetraplegia” was more common in Europe and in more formal medical and rehabilitation literature than quadriplegia.

As spinal cord injury classification systems were updated and standardized internationally, professional organizations began recommending “tetraplegia” as the preferred term in the following:

• Research articles

• Textbooks

• Official classification documents

One of the reasons was specifically to clean up the language: if “paraplegia” is Greek‑Greek, then the term for paralysis of all four limbs should also be Greek‑Greek.

So in formal medical settings, you’ll often see:

Tetraplegia (quadriplegia)

This is simply a way of saying: “We’re using tetraplegia as our official term, but we recognize that people also say quadriplegia.”

I would assume anything that is published in a medical journal going forward will use the word “tetraplegia.”

Why “Paraplegic” Stayed the Same

You might wonder: if “quadriplegic” changed to “tetraplegic,” why didn’t “paraplegic” change?

Because paraplegia was already:

• Built from Greek‑Greek roots

• Well‑established in both everyday and medical language

Paraplegia refers to paralysis that typically affects the legs and lower body, usually due to injuries at the thoracic, lumbar, or sacral levels of the spinal cord.

There was nothing to “fix” linguistically, so paraplegia remained paraplegia. The main adjustment was simply bringing “quadriplegia → tetraplegia” in line with the same pattern.

Which Term Should You Use?

From a practical standpoint,

• In everyday conversation, especially in the U.S., people commonly say “quad” or “quadriplegic.”

• In medical charts, research papers, and official standards, you’re more likely to see “tetraplegia” or “tetraplegia (quadriplegia).”

Here’s how I approach it:

In formal writing, tetraplegia is used.

In conversations with patients and families: I mirror the language the person uses. If they call themselves a “quad,” I respect that and use their term.

There is no “wrong” choice in a normal conversation. Both terms are widely understood. The key is to respect how each person describes themselves.

Why This Language Detail Matters (and Why It Doesn’t)

On one level, this is just a terminology clean‑up story – getting Greek and Latin straight.

However, it also reflects something bigger:

The spinal cord injury community has worked hard to have clear, consistent, and respectful language to describe different levels and patterns of injury.

This consistency helps with research, rehabilitation planning, and communication across different hospitals, countries, and specialties.

At the same time, language is personal:

• Some people choose to proudly identify as a “quad.”

• Others prefer “tetraplegic.”

• Some do not like either label and focus more on what they “can do” rather than the word used.

It is probably best to assume that they are “a person with quadriplegia, paraplegia, tetraplegia” instead of a quadriplegic, paraplegic, or tetraplegic. Focus on the person with a condition and not just a condition defining the person.

You will find some people care about this, while others do not.

Therefore, terminology is important for clarity and science.

What I’ll Cover Next

In future issues of Spinal Cord Thrive, I plan to write about topics such as:

1. How doctors classify spinal cord injuries (and what those ASIA / ISNCSCI letters and numbers really mean)

2. Autonomic dysreflexia

3. The difference between UTI versus colonization

4. Temperature dysregulation and poikilothermia in spinal cord injury

If there is a specific topic you would like me to break down in plain language, hit reply and let me know—I read those messages and use them to decide what to tackle next.

Key Takeaways

1. “Quadriplegic” and “tetraplegic” describe the same pattern of paralysis: involvement of “all four limbs,” usually from a cervical spinal cord injury.

2. The shift toward “tetraplegia” in professional settings was mainly to make the terminology linguistically consistent (Greek + Greek), in line with “paraplegia.”

3. “Paraplegia” stayed the same because it already fit that pattern and refers to paralysis mainly of the “legs and lower body.”

4. In real life, especially in the U.S., people use “quadriplegic,” “tetraplegic,” and “quad” interchangeably. What matters most is respecting how each person chooses to describe themselves.

I hope this helps clarify the terminology and provides insight into how the SCI world came to use two different terms for the same concept.

Glen House, MD

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In a recent Spinal Cord Thrive (Thrive 11) article, I walked through how continuous glucose monitors (CGMs) can reveal blood sugar patterns you’d never suspect just by “eating healthy.” Many users are surprised to see which foods cause big glucose spikes on their own graphs.

This follow‑up newsletter discusses why this occurs and where to start if you want to bring your glucose under control, especially after spinal cord injury. We need to fix the two biggest drivers of metabolic chaos: added sugars and refined carbohydrates.

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Why Start Here?

Before you subscribe to any diet philosophy—keto, Mediterranean, carnivore, low‑fat, or plant‑based—there are two fundamentals that apply universally. They are not about ideology; they are about physiology. You cannot build metabolic health or stable energy until you get sugar and refined carbohydrates under control.

For people living with spinal cord injury (SCI), this is even more critical. Reduced muscle mass and limited mobility make glucose metabolism problematic. However, the same two first interventions work for everyone.

• Eliminate added sugar.

• Eliminate refined carbohydrates from the diet.

Everything else in nutrition becomes easier once you do these two things.

Refined carbohydrates are grains and starches that have had most of their natural fiber and nutrients stripped away, such as white flour, white bread, pastries, and many packaged snack foods. They act a lot like straight sugar in your body, causing your blood sugar and insulin levels to spike quickly and then crash.

Step 1: Eliminate Added Sugar

When I say eliminate added sugar, I mean eliminate it completely, or as close to it as you reasonably can. This single step often shifts metabolism more than almost any other change.

Not all sugars are the same. Some foods naturally contain sugar—like the lactose in plain yogurt or the fructose in whole fruit—and that’s expected. What you really need to watch for on labels is added sugar, which is any sugar the manufacturer has poured in on top of what was already there naturally.

When the food industry pivoted to “low‑fat” everything, there was a big, unspoken problem: once the fat was removed, the food tasted terrible. To make these products palatable, manufacturers started pouring sugar into almost everything because sugar has no fat. For years, we were trained to feel virtuous grabbing items labeled “low fat” or “fat free,” not realizing that the missing fat had been replaced by added sugar, quietly driving blood sugar and insulin higher while the front of the package told us we were making a healthy choice.

Added sugar is not just the white crystals that you pour into coffee. It hides in:

• Sauces and dressings

• Breads and tortillas

• Protein bars and “energy” bars

• “Low‑fat” or “light” products

• Granola, flavored yogurt, and foods boldly marketed as “healthy”

The modern food environment has made sugar nearly unavoidable because it is cheap, addictive, and reliably makes food taste good. This means that you need a skill that most people have never learned: reading labels as if your health depends on it—because it does.

How Much Sugar Is “A Lot”? Introducing the Glazed Donut Index (GDI)

The numbers on a label—10 grams here, 18 grams there—can feel abstract. To make this a reality, I use what I call the Glazed Donut Index (GDI). One Krispy Kreme–style glazed donut has approximately 10 g of sugar; therefore, for the GDI, we simply set:

• 1 GDI = 10 grams of sugar

This means that every food can be translated into glazed donut equivalents.

The Glazed Donut Index (GDI)

The Glazed Donut Index (GDI) makes the amount of sugar relatable.

• 1 GDI = 10 grams of sugar (the amount of sugar in one glazed donut)

Once you know this, you can translate any label into donut equivalents.

• 10 g sugar = 1 GDI (1 glazed donut)

• 20 g sugar = 2 GDI (2 donuts)

• 30 g sugar = 3 GDI (3 donuts)

Therefore, yogurt with 27 g of sugar is not “just yogurt”— it is 2.7 GDI, or 2.7 glazed donuts in a cup, and a bottled latte with 35 g of sugar is 3.5 GDI, or 3½ donuts in a drink.

This is exactly how I describe it to my patients in the clinic: we run their favorite foods through the Glazed Donut Index, and they are almost always shocked when they suddenly see their “healthy” choices as two, three, or even four donuts worth of sugar.

Now, every food can be translated into glazed donut equivalents when you read the label. A flavored yogurt that looks like a smart breakfast choice may have 27 g of sugar—2.7 GDI, or 2.7 glazed donuts in a cup. A “natural” granola barmay sit around 20 g —2 GDI, or 2 donuts in a wrapper. A sweetened bottled coffee or latte can easily run 30–40 g —3–4 GDI, or 3–4 donuts in a cup.

You would never sit down and eat three glazed donuts for breakfast and call it a healthy move. However, many people consume these sugars in liquid or “health‑food” form, completely unaware of their harmful effects.

When I say this, many of my patients jokingly say they would rather have a glazed donut. I’m not suggesting you eat the donut instead. The point is awareness. Once you start translating grams of sugar into the Glazed Donut Index, the label reading becomes very concrete very quickly.

Step 1.5: Learn to Spot Hidden Sugar

Food companies know that “sugar” does not sound great on a label, so they use many different names. When you read ingredients, you’re not just looking for the word “sugar.” You are looking for the entire family.

The “‑ose” Family

Anything ending in “‑ose” is a form of sugar:

• Glucose

• Fructose

• Sucrose

• Dextrose

• Maltose

• Lactose

Syrups and Concentrates

• Corn syrup

• High‑fructose corn syrup

• Brown rice syrup

• Rice syrup

• Barley malt syrup

• Maple syrup

• Agave nectar or agave syrup

• Golden syrup

Other “Natural”‑Sounding Sugars

• Honey

• Molasses

• Cane sugar, cane juice, evaporated cane juice

• Coconut sugar

• Turbinado sugar

• “Raw” sugar

• Fruit juice concentrate

Two practical rules:

• If one of these appears in the first three ingredients, the product is a sugar delivery system, no matter how “healthy” the box looks.

• If you see several different sugars sprinkled throughout the list, the manufacturer is usually splitting one big sugar load into multiple small names so it does not look like “sugar” is the main ingredient.

Between the “Added Sugars” line on the Nutrition Facts panel and these ingredient names, you can quickly decide whether a food supports your goal—or quietly works against it on your GDI tally.

What Happens When You Cut Added Sugar?

Cutting added sugar does more than just reduce calories. It changes hormones.

Chronic sugar intake keeps insulin levels elevated. Insulin is the master metabolic signal that tells your body to store energy. When insulin is high:

• Fat gets locked inside fat cells.

• Fat burning is shut down.

• Hunger and cravings tend to rise.

• Energy becomes dependent on frequent sugar “hits.”

By clearing out added sugar, insulin can fall. When it does, fat becomes available as a fuel source. Many people notice the following within days:

• Energy becomes steadier.

• Hunger and cravings are less intrusive.

• Your mind is clearer, not in a fog.

• The “afternoon crash” softens or disappears.

For individuals with spinal cord injury, who are already facing challenges with muscle mass and glucose disposal, this hormonal shift is even more valuable. You are asking the metabolism to work with fewer levers, so you want the levers you still have, like insulin sensitivity, working well.

Step 2: Eliminate Refined Carbohydrates

If sugar is the first metabolic disruptor, then refined carbohydrates are the second. They are essentially sugars in disguise.

Refined carbs include:

• White bread and rolls

• Most crackers and chips

• Pastries, cookies, cakes

• Many breakfast cereals

• Most packaged snack foods made from refined flour

For the general reader, refined carbs can be thought of as grains and starches that have had most of their natural fiber and nutrients stripped away, such as white flour, white bread, and many snack foods. They act a lot like straight sugar in your body, causing your blood sugar and insulin levels to spike quickly and then crash.

Your body does not experience these as gentle, slow-burning fuel. It experiences them as rapidly absorbed glucose. The result is the same pattern as added sugar:

• Rapid blood sugar spike

• Insulin surge

• Fat storage mode

• Energy crash and cravings on the other side

You may be eating what you think is a “low‑fat” or “plant‑based” diet and still be on a blood sugar rollercoaster all day if it is heavy in refined grains and starches.

Simple Rules for the Real World

To make this actionable, use two simple rules:

• Shop the perimeter. That’s where the real food lives—vegetables, fruits, meat, fish, and eggs. The inner aisles are where you find boxes, wrappers, and barcodes—where refinement, added sugar, and a rising GDI usually live.

• If you can’t pronounce it, don’t eat it. Real food doesn’t need a long ingredient list. If something has one ingredient—“broccoli,” “apple,” “salmon,” “eggs”—it will almost always beat the product with 15 chemical-sounding names.

These rules aren’t perfect, but they’re simple, practical, and easy to remember—exactly what you need when you’re tired, busy, and in a crowded grocery store.

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Using a Macro‑Tracking App as Another Lens

Along with reading labels and using tools like CGMs, I also encourage patients to try a nutrition/macro‑tracking app for at least several months to track your carbohydrate intake. There are many free options; one I have used is MyFitnessPal, which has a free version if you can tolerate some ads at the bottom.

The point is not to count every calorie forever. It is to build awareness:

• How many total grams of carbohydrate are you really eating in a day?

• How much of that is coming from obvious sugar versus refined starches?

When I was targeting lower carbohydrate intake, my goal was to stay under about 50 grams of total carbs per day—and I focused on total carbs, not “net carbs” (which subtract fiber). You do not have to use that exact number, but tracking for a short period provides honest data to pair with your GDI estimates and CGM readings. Together, these three perspectives—labels, GDI, and app-based macros— provide a clear picture of what your metabolism is actually facing.

A Day in the Life of Hidden Sugar (and GDI)

Here’s what a fairly typical “trying to be healthy” day can look like:

Breakfast

• Flavored fruit yogurt (≈ 2.7 GDI)

• Granola sprinkled on top (≈ 1 GDI)

Mid‑morning

• “Natural” granola bar (≈ 2 GDI)

Lunch

• Turkey sandwich on soft white bread (hidden sugars in bread and sauce, ≈ 1 GDI)

• Small flavored yogurt cup (≈ 1.5 GDI)

Afternoon

• Bottled iced coffee or sweet latte (≈ 3.5 GDI)

Evening

• “Light” dessert or a small bowl of sweetened cereal (≈ 1.5–2 GDI)

By the end of the day, this person has quietly reached 13–14 GDI—the sugar equivalent of 13–14 glazed donuts—without ever stepping into a donut shop. On paper, it looks “healthy”: yogurt, granola, a sandwich, coffee, and a small dessert. Metabolically, it behaves like a steady drip of donuts from the morning to the night.

Now compare that to a lower-GDI, perimeter-of-the-store day:

Breakfast

• Plain Greek yogurt (unsweetened), full‑fat or low‑fat, with a handful of berries and chopped nuts (very low GDI)

Mid‑morning

• A handful of nuts

Lunch

• Salad with mixed vegetables, olive oil, vinegar, and grilled chicken or fish

Afternoon

• Unsweetened iced tea, black coffee, or water

• A cheese stick or a boiled egg if hungry

Evening

• Baked fish or meat, non‑starchy vegetables, and possibly a small portion of whole, intact carbohydrate (like lentils or beans), if it fits your plan

In this second day, added sugar is close to zero and refined carbs are dramatically reduced. On the Glazed Donut Index, the first day is in double digits, and the second day may barely reach 1–2 GDI—a completely different hormonal and metabolic environment, even though both days would look “normal” from the outside.

Day after day, week after week, this adds up and has a significant effect on health. Glucose and insulin levels are low, and fat begins to be used as fuel. This means that visceral adipose tissue begins to dissolve, along with the negative metabolic health consequences described in an early Thrive newsletter.

The “Oh My Goodness” Section: Glazed Donut Index Examples

To drive the point home, it helps to see how a range of common “healthy” or everyday items stack up on the Glazed Donut Index. Using 1 GDI = 10 g sugar, the following examples were obtained:

• Krispy Kreme Original Glazed donut: 10 g sugar → 1 GDI

• Flavored “fruit‑on‑the‑bottom” yogurt: ~24–27 g → 2.4–2.7 GDI

• Sweetened Greek‑style strawberry yogurt: ~23 g → 2.3 GDI

• Dessert‑style yogurt with mix‑ins: ~24–26 g → 2.4–2.6 GDI

• “Natural” granola bar: ~20 g → 2 GDI

• Sugary protein/energy bar: ~18–24 g → 1.8–2.4 GDI

• Bottled sweetened cold brew or latte: ~20–22 g → 2–2.2 GDI

• Chain iced coffee drink with syrup (medium): ~30–40 g → 3–4 GDI

• Large specialty/frozen latte: can exceed 100 g → 10+ GDI

• 32‑ounce regular sports drink: ~56–76 g → 5.6–7.6 GDI

• 20‑ounce regular soda: ~65 g → 6.5 GDI

• Sweetened bottled iced tea: ~30–40 g → 3–4 GDI

• Sugary breakfast cereal (1 serving): ~12–16 g → 1.2–1.6 GDI

• “Healthy” granola with dried fruit (small bowl): ~15–20 g → 1.5–2 GDI

• Flavored instant oatmeal packet: ~12–15 g → 1.2–1.5 GDI

• Yogurt drink / smoothie bottle: ~25–30 g → 2.5–3 GDI

• Sweetened plant milk (vanilla/chocolate, 1 cup): ~12–20 g → 1.2–2 GDI

• Flavored protein bar marketed as “energy” or “meal”: ~20–26 g → 2–2.6 GDI

• Kids’ yogurt tube/pouch: ~10–14 g → 1–1.4 GDI

Most people would never willingly eat five or six donuts a day, yet many unknowingly drink or spoon their way to obesity. The Glazed Donut Index makes this reality impossible to ignore.

Why These Two Steps Work

The pairing of low-added sugar and low refinement is powerful because it restores what modern food has broken: metabolic flexibility.

With lower sugar and fewer refined carbohydrates:

• Insulin levels decreased.

• Fat can once again be mobilized and burned for fuel.

• Inflammation usually decreases.

• Hunger and cravings become more manageable.

This foundation is essential for individuals living with spinal cord injuries. You cannot change the injury itself, but you can profoundly influence the metabolic environment in which your body is trying to heal and function.

These first two steps are not advanced strategies or niche hacks. They are biochemical prerequisites for health, regardless of which “diet camp” you identify with. Once they are in place, you can decide how you want to structure your protein, fat, and unrefined carbohydrates to fit your preferences and circumstances.

Where Continuous Glucose Monitors Fit In

In an earlier Spinal Cord Thrive article, I showed how CGMs provide a real-time window into your blood sugar patterns over the course of the day. CGMs do not care about marketing, healthy labels, or good intentions. They simply show what your body is actually doing in response to what you eat.

When you start applying these two principles—eliminating added sugar and refined carbohydrates—CGMs often reveal something important: many of your biggest glucose spikes are coming from foods you thought were harmless, or even “healthy.” A favorite flavored yogurt, a daily oat milk latte, or a certain brand of “natural” granola bar can light up your CGM in ways that a simple label glance never warned you about, and you can see your GDI in real time.

This feedback can be uncomfortable at first, but it is also empowering. Instead of guessing, you can determine which foods keep your glucose levels relatively flat and which ones send them into a rollercoaster. The patterns are often surprising. Many people discover that a home-cooked meal of protein and vegetables produces a much calmer glucose profile than their “healthy” smoothie, cereal, or snack bar, even when the calories look similar.

Used this way, CGMs become a powerful teaching tool. They confirm in your own body what the physiology predicts: when you get rid of added sugar and refined carbs, the CGM trace quiets down. Spikes become smaller, crashes become less frequent, and your day looks less like a mountain range and more like gently rolling hills.

That is what metabolic control looks like on a graph—and it is the same foundation that allows you to build the rest of your nutrition strategy with confidence, one Glazed Donut Index point at a time.

Summary

• Two foundational steps—eliminate added sugar and refined carbohydrates.

• The Glazed Donut Index (GDI) translates grams of sugar into donut equivalents, making the hidden sugar instantly obvious.

• Hidden sugars, especially in “healthy” products, quietly drive insulin spikes, fat storage and energy crashes.

• Simple rules (shop the perimeter, avoid unpronounceable ingredients), a macro‑tracking app, label reading, and CGMs together give you a powerful, practical framework for regaining metabolic control.

Glen House, MD

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By the time a doctor says, “You have diabetes,” that process has often been unfolding for years. But here’s the truth: it doesn’t have to keep going. You can catch it. You can measure it. And you can reverse it.

That’s why the continuous glucose monitor (CGM) is, in my opinion, the most important health tool available to anyone living with paralysis.

The CGM Is the Golden Lasso

I call it the Golden Lasso, a reference to Wonder Woman’s truth-telling rope. Once you wear a CGM, your food choices can’t lie to you anymore. You know exactly what every meal, snack, and drink does to your blood sugar. It creates instant accountability because it’s your data, your truth, and your health displayed right in front of you.

That feedback loop is transformative. You start making better choices naturally because you know how they affect you. You don’t need willpower; you need feedback that you’ve never had before.

Key Lessons From My CGM Data So Far

1. Hidden spikes are everywhere.
Even foods that seem “healthy,” like a smoothie, oatmeal, or “low-fat” yogurt, can trigger glucose surges I never would have guessed without watching in real time. Oh, I have so much to show you.

2. Some foods, when eaten in combination, have different spike levels.
Eating some carbohydrates alone versus with protein, or after protein, can lead to very different spike heights and durations. Bread or potatoes alone can look very different compared with the same foods eaten with protein.

3. Fatigue and low energy follow glucose swings.
When my glucose stays stable, I feel sharper and more focused. When it fluctuates widely, fatigue hits hard. This isn’t coincidence. It’s physiology you can watch unfold.

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My Journey and What’s Coming Next

When I first started tracking blood sugar and ketones, I used a Keto Mojo meter. It required multiple daily fingersticks and a lot of manual effort. Once I switched to a CGM, everything changed. I could finally see why some days felt great and others didn’t. Glucose would rise and stay elevated after certain foods, even ones I thought were harmless.

I still use the Keto Mojo meter to follow my ketones occasionally. After months and even years, I began to know how to eat and can predict what I eat will do to my sugar or my ketones.

My personal goal now is to keep my spikes under 140–150 mg/dL and to keep my blood sugar (glucose) as low as possible and under 100 mg/dL at all times. That’s the sweet spot for minimizing spikes and controlling insulin demand. I also track ketones (especially when starting and learning), aiming for 0.5–3.0 mmol/L, which indicates I’m in nutritional ketosis and efficiently burning fat, including the visceral fat that drives insulin resistance.

In future newsletters, I’ll share my own CGM results, showing how different foods, routines, and even stress affect glucose levels. I’ll demonstrate “good” and “bad” spikes intentionally, not because I would normally do them, but to show what’s happening inside your body when you do. What I’ve already discovered has completely changed how I live and eat.

The Science of Reversal

Here’s something most people don’t realize: type 2 diabetes is not a life sentence. The evidence is clear that insulin resistance and early-stage diabetes can often be stopped and even reversed with the right changes in diet and lifestyle.

Programs like Virta Health have shown in peer-reviewed research that people with type 2 diabetes, even those on insulin, can normalize their blood sugar and discontinue medications through a low-carbohydrate, ketone-based approach.
Many other clinical trials report the same thing. When you reduce glucose fluctuations and lower insulin demand, your body begins to heal.

This isn’t fringe science. It’s basic metabolic physiology. When glucose stabilizes, insulin normalizes. When insulin normalizes, fat begins to mobilize. As visceral fat decreases, inflammation and insulin resistance improve together. It’s a chain reaction that leads to real recovery.

A CGM isn’t just a diagnostic tool. It’s the first step toward reversal. It lets you see how your habits shape your metabolism, minute by minute, and guides you toward stability and repair.

Why Insurance Still Doesn’t Cover It and Why That’s Wrong

Here’s what’s so frustrating: most insurance plans only cover CGMs once you’re insulin-dependent, usually with type 1 diabetes or advanced type 2 diabetes. That’s like refusing to give someone a seatbelt until after a car crash.

This policy ignores prevention, ignores science, and punishes early action. People with spinal cord injuries are especially vulnerable to metabolic disease because of the rapid body composition changes that occur after injury. Early glucose monitoring should be standard care, not a privilege.

Today, it’s possible. You can buy FDA-approved, non-prescription CGMs like the Dexcom Stelo and Freestyle Lingo directly online without a doctor’s prescription. A three-month supply costs about $250, far less than a single ER visit or ongoing medication costs. Consider it an investment in your health. That’s about $2.70 per day and much less than a cup of coffee at Starbucks.

If cost is an issue, I encourage people to start a GoFundMe dedicated to tracking and improving their metabolic health. Ask your friends and family to help support your long-term health. Imagine the impact: a community of people with paralysis using real-time data to reclaim control.

The Bottom Line

You are not locked into a future of diabetes, vascular disease, or metabolic decline. The same process that raised your glucose can be stopped, reversed, and healed, but only if you can see what’s happening in real time.

A CGM makes that possible. It’s the golden lasso that reveals the truth and gives you the power to act on it.

If you have a spinal cord injury, wear one, even for a few months. Watch what happens to your numbers, your energy, and your cravings. Once you see your own truth, you’ll make better choices naturally, not out of fear, but out of understanding.

That’s how we change the future of paralysis care: through knowledge, visibility, and personal accountability.

Upcoming CGM Demonstration Series

In future newsletters, I’ll share real CGM data from my own monitoring: what meals cause spikes, how I stabilized them, and what small dietary changes made the biggest difference. I’ll occasionally include intentional “glucose mountains” to show how harmful foods affect the curve and how quickly balance can return when you make the right choices.

This is going to be eye-opening. You’ll see exactly what’s happening inside your body, using raw data, graphs, and screenshots straight from my CGM.

Glen House, MD

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References

1. Hallberg SJ, et al. Effectiveness and Safety of a Novel Care Model for the Management of Type 2 Diabetes at 1 Year: An Open-Label, Non-Randomized, Controlled Study. Diabetes Ther. 2018;9(2):583–612.

2. Snorgaard O, et al. Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes. BMJ Open Diabetes Res Care. 2017;5(1):e000354.

I committed to a very low-carbohydrate way of eating. I was no longer satisfied with the explanation that I would forever have poor metabolic health because of my spinal cord injury. I knew the data on reduced life expectancy after SCI, but I was determined to change that trajectory for my own life.

For years, my lab work had been sending a quiet but consistent message: HDL in the 20s, high triglycerides, fasting glucose creeping up, hemoglobin A1c drifting in the wrong direction. It was the same pattern I had seen in the literature and in my own patients with chronic spinal cord injury — Paralysis Metabolic Dysfunction playing out in real time in my own life.

Changing my diet was a decision. The question was whether my biology would answer.

It did.

Over the months that followed, my lab values began to shift. HDL climbed. Triglycerides dropped. Fasting glucose stabilized instead of inching upward. A1c fell from high-normal into the middle of the range. The pattern that had been tracking toward metabolic syndrome started to dramatically reverse.

But even that wasn’t the full story.

What ultimately convinced me that I had fundamentally changed my metabolic trajectory was not a single fasting lab. It was what happened when I followed the trend of all of my metabolic biomarkers and saw that everything was shifting in a positive direction.

Why Fasting Labs Can Be Misleading After SCI

Most routine screening in primary care leans heavily on fasting labs. If your fasting glucose is around or slightly above 100 and your A1c is in the “normal” high range (5.4-5.6), the usual message is some version of, “You’re fine. Keep doing what you’re doing.” That may be the message even if many of your other metabolic and inflammatory markers are heading in the wrong direction.

If you don’t look, you will not know what is happening inside your own body. Information is knowledge. With the right information, we can do something about it or change directions if needed.

For someone with a spinal cord injury, limited information can be dangerously incomplete.

Fasting numbers alone give you an incomplete and sometimes false picture of your metabolic status. They do not tell you what happens when you actually challenge the system with a real glucose load. They do not show you how high your sugar goes, how long it stays there, or how much insulin it takes to drag it back down.

In someone with paralysis — with large amounts of muscle below the level of injury that are not contracting and not clearing glucose, with impaired insulin signaling, and with visceral fat quietly accumulating — that matters. You can have fasting values that look “normal enough” while your post-meal and post-challenge responses are already in the pre-diabetic or diabetic range.

I wanted to know what was really happening under the hood, metabolically.

So, after years of living with a very low-fat approach, I did something that felt almost like a controlled experiment on myself: I drank a large, standardized glucose load and watched what happened to my blood sugar.

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The Oral Glucose Tolerance Test: Stress-Testing the System

An oral glucose tolerance test (OGTT) is exactly what it sounds like: you drink a defined amount of glucose (typically 75 grams), and blood samples are taken over a set period of time to see how your body handles the load. For my personal experiment, I wore a continuous glucose monitor (CGM) for ongoing measurement and the most complete data collection. I used a Freestyle Libre 3 CGM, which samples the interstitial fluid between the cells every minute. This typically lags behind actual blood sugar by 5 to 15 minutes, but it is an ideal way to see exactly how your blood sugar responds over time.

When I underwent my OGTT after years of living with a spinal cord injury, I approached it with a mix of curiosity and realism. I knew what the literature said about glucose intolerance in chronic SCI, and I knew fasting labs alone might underestimate the degree of risk.

My results showed what I expected — and worse. Based on the results, I could be classified as a person with type 2 diabetes, with a blood glucose at one hour at 275 and a blood sugar at two hours at 203. That is the definition of a system that is beyond insulin resistant.

Here is the key point: an OGTT like this is not something you “fix” with diet. The curve is essentially revealing the fixed insulin resistance that comes with reduced muscle mass, impaired signaling, and paralysis. Changing how you eat does not suddenly make your OGTT look like that of a metabolically healthy, able-bodied person.

What diet does change is your exposure to that impaired system. By shifting to a very low-carbohydrate pattern, you dramatically reduce how often and how high your glucose spikes, which in turn changes your hemoglobin A1c over time — even if your fasting glucose barely moves and your underlying insulin resistance remains. In other words, the OGTT and fasting glucose tell you that you are insulin resistant; the very low-carbohydrate diet is how you live around that reality, with fewer spikes and a lower A1c, not how you erase it.

• In a metabolically healthy system, blood glucose rises, insulin is released, GLUT4 transporters in muscle pull sugar out of the circulation, and levels return toward baseline within a short, predictable window.

• In an insulin-resistant system — especially one with reduced muscle mass and impaired activity after SCI — the curve looks very different: glucose spikes higher, stays elevated longer, and requires much more insulin to control.

The point is not that the OGTT was “perfect.” The point is that it revealed dynamics that a simple fasting blood glucose sample never could — and that those dynamics guided me toward a way of eating that reduced my exposure to glucose and insulin, even though my underlying insulin resistance and OGTT pattern remained.

The Lab Pattern That Told the Story

Taken together, my lab changes painted an undeniable before‑and‑after picture:

Low-Fat —> Very Low-Carbohydrate!!!

• HDL cholesterol: Low and stubborn in the 20s for years (described as typical for spinal cord injury), then rising into a healthier range (in the 60s) after sustained very low-carbohydrate eating.

• Triglycerides: High and compatible with insulin resistance before, then falling substantially as dietary carbohydrate decreased and insulin demand dropped — now measuring below my HDL level and reaching the 40s.

• Fasting glucose and A1c: Creeping upward on a low-fat, high-carbohydrate diet, then stabilizing and improving once carbohydrate became the minority of my intake.

• Other metabolic biomarkers: Improving across the board (HOMA-IR, fasting insulin, homocysteine, lipid panel, hsCRP), shifting from an inflammatory state to a normal range as long as I maintained this very low-carbohydrate, low-insulin (nutritional ketosis) approach.

These numbers are not just academic. In the context of spinal cord injury, they map onto real outcomes: risk of type 2 diabetes, cardiovascular disease, fatty liver, and the whole cluster of complications that fall under the umbrella of Paralysis Metabolic Dysfunction.

For me, watching these markers move in the right direction was biochemical confirmation of what I was feeling subjectively: more stable energy, no crashes, a body that was no longer being pushed, day after day, into a state of chronic overexposure to repeated surges of glucose and insulin.

Why the Real Target Was Insulin All Along

Looking back, it would be easy to say, “The answer was a very low-carbohydrate diet.” But that misses the deeper point.

The real target was insulin.

Carbohydrate intake is one of the most powerful levers we have over insulin levels, especially in a body where the primary tissue for glucose disposal — skeletal muscle — has been partially taken offline by paralysis. For years, I had been eating in a way that kept my insulin elevated, even if each individual meal looked “healthy” by conventional low-fat standards.

By systematically lowering my carbohydrate exposure, I lowered the demand on my insulin system. Lower insulin meant less drive toward visceral fat accumulation, less chronic inflammation, and less ongoing strain on the insulin-signaling pathways that were already vulnerable after my injury. The very low-carbohydrate pattern was simply the tool that allowed me to do that consistently in my real life with tetraplegia.

What This Means for You If You’re Living With SCI

This is still my story. It is not a prescription.

But if you are living with a spinal cord injury and your labs are showing the same pattern mine did — low HDL, high triglycerides, slowly rising glucose and A1c — it may be a signal that your current way of eating and your underlying physiology are working against each other.

A few questions you might consider with your own medical team:

• Are fasting labs giving you the full picture, or would a glucose challenge test reveal something different about how your body handles sugar?

• Is your current diet structured around what is convenient, familiar, or officially recommended — or around what your paralyzed muscle and insulin-signaling pathways actually need?

• If you focused less on a “named diet” and more on lowering your insulin exposure, how might that change the way you approach food?

There is no single “right” path for everyone after SCI. But there is a right set of questions.

For me, asking different questions — about insulin, about glucose disposal, about how my labs were trending instead of whether they were “still in range” — is what opened the door to changing my trajectory. Parts 1 and 2 of this series told the story of how I got here and what I changed. Part 3 is simply the evidence that it mattered.

This series is part of the Spinal Cord Thrive educational project. If you haven’t yet, reading the earlier “Thrive” articles in order will give you the scientific framework behind the story you’ve just read, and may help you start writing a different metabolic story of your own.

Glen House, MD

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When the pieces finally clicked — when ‘Good Calories, Bad Calories’ convinced me that the low-fat, high-carbohydrate diet I’d been following was misaligned with both the science and my spinal cord injury — I still had a problem.

Knowing is not the same as changing.

It is one thing to read a book, close the cover, and say, “Wow, that explains a lot.” It is another thing entirely to look at your own health and dietary habits and decide to do things differently and consistently. I looked at my labs and my metabolic health and realized that my numbers were not consistent with long-term health and longevity in the setting of a spinal cord injury.

I determined that the status quo was no longer an option for me.

My HDL had been stuck in the 20s. My triglycerides were high. My fasting glucose was creeping up. I had seen enough patients — and enough literature — to know exactly where that road leads in chronic SCI. The question in front of me was no longer “Is this ideal?” It was “Am I willing to keep going in this direction?”

I wasn’t.

So I did something that, at the time, felt almost radical: I started removing carbohydrates from my diet on purpose.

From Low-Fat to Very Low-Carb

The first decision I made was conceptual, not numerical: I stopped thinking of fat as the enemy and started thinking of insulin as the central variable I wanted to keep low. A low-fat diet, by definition, becomes a higher-carbohydrate diet. A higher-carbohydrate diet, especially in the context of paralyzed muscle and impaired GLUT4 activity, means more frequent and higher insulin spikes. Over time, those spikes and higher insulin drive the visceral fat, inflammation, and insulin resistance that define Paralysis Metabolic Dysfunction.

The alternative was obvious on paper and daunting in real life: a very low-carbohydrate diet.

Here is what that transition looked like in practice for me:

• I stopped basing meals around bread, pasta, rice, and potatoes. Those foods were strictly eliminated.

• I brought fat back on purpose: whole eggs instead of egg whites, full-fat dairy instead of skim, fatty cuts of meat instead of only the leanest options.

• I prioritized higher healthy fats, moderate protein, and low-carbohydrate vegetables as the backbone of every meal.

If you want a label, what I did would be considered “very low-carb” by most standards and often ketogenic, especially early on. In more technical terms, I shifted from a pattern where the majority of my calories came from carbohydrates to a pattern where carbohydrates were the minority and higher fats with moderate protein made up most of the difference.

My goal was to lower my carbohydrate intake, which would lower my insulin and trigger an adaptation of my metabolic machinery.

Doing This With Tetraplegia

It would be easy to tell this story as if it were just a matter of willpower and grocery lists. It wasn’t. Living with tetraplegia changes everything about how food shows up in your life.

There are realities that anyone with SCI will recognize:

• You may rely on others for shopping, meal prep, or, in some situations, feeding.

• Energy is limited. Fatigue, spasticity, pain, and prolonged morning schedules compress the amount of time and bandwidth you have to think and plan about food.

Any dietary approach that ignores those realities is doomed from the start.

So instead of designing a perfect diet on paper and trying to cram my life into it, I took the opposite approach: I looked at my actual routines and constraints and asked, “Where are the leverage points? What can I change that will give me the biggest metabolic payoff for the least disruption?”

A few examples of what that looked like:

• Simplifying meals: Rather than elaborate recipes, I leaned on simple combinations that could be repeated: eggs and cheese; meat and non-starchy vegetables; Greek yogurt with a few berries and nuts. Fewer decisions meant better adherence.

• Standardizing the environment: If high-carbohydrate foods were in the house, they were more likely to be eaten. So I made a deliberate effort to take those temptations away.

• Planning: I created a short list of go-to meals that were easy to prepare and repeat.

This is important: none of this was about moral purity or perfection. It was about engineering my surroundings so that the “default” option was more often aligned with the metabolic reality of living with paralysis.

What Changed in My Day-to-Day

The first changes I noticed were not on lab reports. They were in the way my days felt.

As I removed large carbohydrate loads from my meals, the roller-coaster of post-meal fatigue and “carb crashes” started to flatten out. My energy became more stable. Hunger felt different — less frantic, more predictable. I could go longer between meals without feeling like my brain was going offline.

Those are subjective experiences, and they matter. But they were not the main reason I committed to this approach.

The main reason was metabolic health. Specifically, the pattern that had been seen in my labs for years: low HDL, high triglycerides, creeping glucose, rising visceral fat. Those numbers are not just abstract markers. In chronic SCI, they map onto real, objective risks: higher rates of metabolic syndrome, cardiovascular disease, and type 2 diabetes than in the general population, even after accounting for age and body mass index.

If there was a way to reverse that pattern — or at least slow it down dramatically — by changing the composition of my diet, that was a lever worth pulling.

Why This Wasn’t About a “Magic Diet”

It is tempting to turn any success story into an argument that one specific diet is the answer. That is not what this series is about.

For me, a very low-carbohydrate approach was the right tool for the job in front of me: a body with tetraplegia, paralyzed muscle that does not clear glucose, impaired insulin signaling, and a lab pattern already moving in the wrong direction. The central therapeutic target was not a brand-name diet. The target was lowering my insulin by changing my nutritional intake.

Different people after SCI will have different preferences, constraints, and medical situations. What matters is whether the way you eat matches the underlying physiology of paralysis or fights against it.

In the next article, I am going to show you what happened when I pushed this approach far enough and long enough for my labs to tell the story: how my HDL, triglycerides, and glucose responded; what my oral glucose tolerance test revealed that my fasting glucose never would have; and why, for someone with SCI, relying on “normal” fasting labs can be dangerously misleading.

This is still my story. But if you are living with a spinal cord injury, watching your numbers drift in the same direction mine did, it may also be a blueprint — not for copying exactly what I did, but for asking a different set of questions about what your food is doing to your insulin, your muscle, and your future.

Glen House, MD

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Around 2014, twenty-four years into living with a C7 spinal cord injury, I picked up a book called Good Calories, Bad Calories by Gary Taubes. I didn’t know it at the time, but that book was going to change the entire trajectory of my metabolic health.

Let me back up.

I was injured in 1990, at age 20, in a skiing accident. From the very beginning, I did everything I was supposed to do — everything the medical establishment and the dietary guidelines told me was right. Throughout the late 1980s and into the 1990s, the message was loud and clear: eat low-fat. Cut the fat out of your diet, replace it with grains and carbohydrates (the bottom of the original food pyramid), and your heart and your health will be better for it. That was the gospel, and I followed it.

For the first twenty-four years after my injury, I ate a very low-fat diet. I chose lean meats, avoided butter, drank skim milk, loaded up on bread and pasta and rice. I was a good patient. I did what I was told.

And my metabolic health got worse.

Not all at once. Slowly. By fifteen years in — around 2005 — the trend was undeniable. The way it happens for many people with spinal cord injuries: quietly, in the background, showing up on lab work that your doctor quickly looks at and says, “Let’s just keep an eye on that.” My HDL cholesterol — the so-called “good” cholesterol — was consistently in the 20s. My triglycerides were high. My fasting glucose was creeping into the low 100s. My hemoglobin A1c was sitting at around 5.5, which is technically “high-normal” but headed in the wrong direction. The pattern was textbook: low HDLs, high triglycerides, rising glucose, smoldering inflammation. It was the same pattern I would later come to understand as Paralysis Metabolic Dysfunction.

My primary care physician’s advice? “Let’s just keep checking. Maybe we’ll put you on some medicine at some point.”

That didn’t sit right with me. But at the time, I didn’t have a better framework. I was doing what the guidelines said. What else was there?

Then I read Good Calories, Bad Calories.

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The History They Didn’t Teach Us

Gary Taubes is a science journalist, and what he did in that book — published in 2007 — was something remarkable. He went back to the original research and traced the history of how the United States ended up with dietary guidelines that told an entire nation to fear fat and embrace carbohydrates. The story he uncovered was not flattering.

It starts with a physiologist named Ancel Keys.

In the 1950s and 1960s, Keys was studying the relationship between diet and heart disease. He became convinced that dietary fat — specifically saturated fat — was a primary driver of heart disease. His landmark work was the Seven Countries Study, which enrolled over 12,000 men across 16 cohorts in seven countries: the United States, Finland, the Netherlands, Italy, the former Yugoslavia, Greece, and Japan. The study showed correlations between saturated fat intake, serum cholesterol, and coronary heart disease rates across these populations.

Here is the problem: Keys had access to data from far more countries than the seven he chose to study. Critics have long pointed out that he selected countries that supported his hypothesis and left out those that didn’t. Countries where people ate high-fat diets but had low rates of heart disease — or ate low-fat diets and had high rates — were not included. It was not the randomized controlled trial that you would need to prove cause and effect. It was observational, ecological data, interpreted through a lens that was already looking for a specific answer.

But Keys was persuasive. He was on the cover of Time magazine in 1961. His ideas gained enormous traction, and the diet-heart hypothesis — the idea that dietary saturated fat raises cholesterol and causes heart disease — became the dominant paradigm.

The McGovern Committee: When Politics Outran Science

The next critical chapter happened in Washington.

In 1977, Senator George McGovern chaired the Senate Select Committee on Nutrition and Human Needs. The committee had originally been created to fight poverty-related malnutrition, but by the mid-1970s it had turned its attention to the relationship between diet and chronic disease — heart disease, cancer, diabetes, obesity.

In January 1977, the committee released Dietary Goals for the United States — the first comprehensive dietary recommendations from any branch of the federal government. The goals were clear: reduce saturated fat to no more than 10% of calories, cut cholesterol to 300 milligrams a day (about 1½ egg yolks), decrease consumption of meat, and increase consumption of complex carbohydrates.

The scientific community was not unanimous. The American Medical Association pushed back, rejecting universal guidelines in favor of individualized physician judgment. Researchers who questioned the diet-heart hypothesis were vocal in their dissent. Even within the committee, there was significant disagreement about whether the evidence was strong enough to justify population-wide recommendations.

But McGovern and his committee moved forward anyway. The political calculus was straightforward: they believed the potential benefits outweighed the risks, and they didn’t want to wait for perfect data. As Taubes documents in his book, the committee’s lead nutritional consultant, Mark Hegsted of Harvard, argued that there were “no known risks” in following the low-fat recommendations and that the risks of not acting were high.

The problem is that there were risks. We just didn’t know them yet.

The Dietary Goals became the foundation. In 1979, the Surgeon General’s report echoed the recommendations. In 1980, the USDA and HHS published the first Dietary Guidelines for Americans, written largely by Hegsted himself. The low-fat message was now official federal policy, and it cascaded into food labels, school lunches, hospital diets, and the advice that every doctor — including the doctors who treated me — gave their patients for the next several decades.

An entire nation was told to cut fat and eat more carbohydrates. And that is exactly what most people did. Over those same decades, obesity and type 2 diabetes rates climbed dramatically — a trend many researchers now connect, at least in part, to those shifts in diet and food environment, even as they debate how much is cause versus correlation.

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What This Meant for Me

I followed the recommendations. For twenty years after my spinal cord injury, I ate the way the government told me to eat. Low-fat. High-carbohydrate. And during that time, my metabolic health deteriorated in the exact pattern that the scientific literature now tells us to expect in chronic spinal cord injury.

What I didn’t understand then — what I couldn’t have understood without the work I’ve done since — is that a person with a spinal cord injury is uniquely vulnerable to the metabolic consequences of a high-carbohydrate diet. The paralyzed muscle below the level of injury doesn’t contract. It doesn’t clear glucose. The GLUT4 transporters that would normally pull sugar out of the blood in response to both insulin and exercise are mostly inactive. The insulin signaling pathway — IRS-1, PI3K, Akt — is impaired. Meanwhile, the body is storing visceral fat, driving inflammation, and becoming progressively more insulin resistant on the way to type 2 diabetes.

I have spent the last several articles in this series explaining the science behind all of this: why muscle fiber type matters, how insulin signaling breaks down after SCI, what visceral fat and chronic inflammation do to the metabolic machinery. That science is not abstract for me. I was living it.

When I read Good Calories, Bad Calories, the pieces came together. The dietary advice I had been following was not only built on questionable science — it was actively working against the specific metabolic vulnerabilities that come with paralysis. Every plate of pasta, every bowl of rice, every slice of low-fat bread was spiking my insulin, driving glucose into a system that couldn’t handle it, and feeding the exact cycle of visceral fat accumulation, inflammation, and insulin resistance that defines Paralysis Metabolic Dysfunction.

The book didn’t just change my mind. It changed my life.

What Comes Next

In the next article, I’m going to tell you exactly what I did about it — how I transitioned from a low-fat diet to a very low-carbohydrate approach, what that looked like practically as a person with tetraplegia, and how I’ve sustained it for the last decade. And in the article after that, I’ll show you the numbers: what happened to my labs, what a glucose tolerance test revealed that my fasting glucose never would have, and why the real goal was never about a specific diet — it was about keeping insulin low.

This is my story. But if you’re living with a spinal cord injury and watching your metabolic health slip in the same direction mine was headed, it might be your story too.

This is part of the Spinal Cord Thrive educational series. For maximum benefit, I encourage you to read the articles in numbered order (Thrive 1, 2, 3, etc.), as each article builds on the knowledge base established in earlier installments.

Glen House, MD

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You Can’t Exercise Your Way Back To “Able‑Bodied” Metabolism

If you live with a spinal cord injury, the exercise targets you see in general guidelines were not written for your physiology. They were designed around big, working leg muscles, an intact sympathetic nervous system, and a resting metabolism that is higher than what almost all people with SCI can achieve.

In motor‑complete tetraplegia, resting energy expenditure (REE) runs about 22% lower than what standard prediction equations would suggest, and some individuals sit under 1,200 kcal per day. Collins and colleagues even proposed that 1 MET for SCI should be reset downward—from 3.5 to about 2.7 mL/kg/min—because the baseline metabolic engine is that much smaller.

In this article, I’ll keep coming back to the idea of energy expenditure (EE). All that means is how much energy your body is using—usually expressed in calories burned over a certain amount of time (per minute, per hour, or per week) during rest and activity.

Quick Note: what is a MET, and why does it matter?

When people talk about “METs,” they’re really just talking about how hard the body is working compared to rest. One MET (1 “metabolic equivalent”) is the amount of oxygen your body uses sitting quietly at rest, standardized in the general population at about 3.5 mL of oxygen per kilogram of body weight per minute. If you’re exercising at 3 METs, your body is using roughly three times that resting amount of oxygen. Moderate‑intensity exercise is usually defined as 3–6 METs, and vigorous as more than 6 METs.

Oxygen use ties directly to calorie burn. As a simple rule of thumb, for every liter of oxygen you consume, you burn about 5 calories. That’s how researchers go from VO₂ and METs to the calorie numbers.

When you start with a smaller engine and less active muscle mass, you simply cannot spend energy at the same rate as someone whose entire lower body is functioning. This is not a failure of effort. It is physiology.

The Hard Numbers: Arm Ergometry and FES In Context

Let’s put some concrete numbers to this, focusing on motor‑complete tetraplegia and paraplegia.

• Motor‑complete tetraplegia, with steady arm ergometry typically burns around 1–3 kcal per minute, rarely exceeding 4–5 kcal/min even at maximal effort.

• Motor‑complete paraplegia, moderate arm ergometry usually burns between about 3–5 kcal/min, with peak values around 7.5 kcal/min that are not sustainable over long sessions.

• FES cycling in complete paraplegia averages roughly 3–6.5 kcal/min (around 288 kcal/hour on average), while typical values in tetraplegia are closer to 2–4 kcal/min.

• Hybrid exercise (arm ergometry plus FES) produces the highest energy expenditure: about 5–7 kcal/min in paraplegia and 3–5 kcal/min in tetraplegia.

Arm Ergometer

When I use the phrase “energy expenditure” here, I’m talking about how many calories your body is burning during exercise. In research, that’s calculated from how much oxygen you use and then converted into calories with that simple rule of 1 liter of oxygen being roughly 5 calories.

To make this concrete, picture two 30‑minute sessions. An able‑bodied person walking briskly might burn around 6 calories per minute—about 180 exercise calories in 30 minutes. Someone with motor‑complete tetraplegia doing arm ergometry at 2 calories per minute for the same 30 minutes will burn about 60 exercise calories. On paper, they both “did 30 minutes of cardio,” but metabolically they are in completely different worlds.

Shea and colleagues estimated that if people with tetraplegia followed SCI‑specific activity guidelines at the “median” intensities actually measured, they would expend only about 563–1,031 kcal per week from that exercise, and total daily energy expenditure would still sit below predicted sedentary levels for the general population. Kressler’s analysis of more than 20,000 FES cycling sessions in 314 users found that not a single user met the classic 1,000 kcal/week threshold for disease prevention with FES cycling alone.

Functional Electrical Stimulation (FES)

The message isn’t “exercise doesn’t work.” The message is: after SCI, the caloric ceiling for safe, realistic exercise is much lower than most guidelines assume or imply.

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A Visual Snapshot: Hours Required To “Hit The Numbers”

Here is a simplified table based on the ranges reported by Shea, Holmlund, Collins, Perret, Hasnan, Farkas, Gorgey, Kressler, and others. It shows approximate hours per week required to reach 1,000 and 2,000 kcal of exercise energy expenditure in complete SCI.

Approximate weekly hours needed to reach 1,000–2,000 kcal from exercise (total hours/week)

How much exercise per day to burn 1,000–2,000 kcal per week (3 days/week)?

Let’s be clear about what the “1,000–2,000 exercise calories per week” recommendation really means after SCI.

• If you’re a C6–C7 tetraplegic relying on arm exercise (ergometer) three days per week, you’d be looking at roughly 2 to 5½ hours per exercise day just to burn 1,000 calories in a week.

  • You would have to exercise for 4 to 11 hours each day to burn 2,000 kilocalories during the week.

• If you’re a paraplegic using only arm exercise three days per week, you’d still need about 1 to 2 hours per day to reach 1,000 calories

  • You would have to exercise around 2 to 4 hours per day to reach 2,000.

When you put it that way, it’s hard not to ask: how long can anyone’s shoulders tolerate that kind of workload before overuse injuries show up?

These numbers are derived from measured VO₂ and caloric data in the lab and in clinical trials, not from theory. For complete tetraplegia using arm ergometry alone, reaching 2,000 kcal per week would mean 14–36 hours of exercise—essentially a part‑time to full‑time job on top of everything else required to live with SCI. Even in paraplegia, the hours needed to consistently hit 1,000–2,000 kcal/week are far beyond what most people can realistically sustain.

The Shoulder “Bank Account”: Why Overuse Risk Changes The Equation

If you have functional upper extremities, your shoulders are not optional. They are your lifeline to transfers, wheelchair propulsion, pressure relief, and self‑care. Every therapeutic arm crank session, every hour of hybrid training, goes through the same tissues that must carry your independence for decades.

The American Spinal Injury Association and Exercise and Sports Science Australia both highlight overuse injuries—especially shoulder pathology—as a key safety concern when prescribing higher volumes of upper‑extremity exercise in SCI. When you ask a shoulder to tolerate 7–36 hours per week of additional repetitive work after spinal cord injury just to chase caloric targets that were never designed for this condition, you are forcing a trade‑off:

• Marginal gains in weekly energy expenditure, versus

• A tangible increase in the probability of rotator cuff tears, impingement, pain, and eventual loss of function.

• Once a shoulder goes, independence goes with it.

A Personal Note: Shoulders, Risk, And Why I Don’t Chase Calories

I want to pause here and speak as a person living with a complete spinal cord injury for more than 36 years at the time of writing this newsletter. I’ve always had to manage the trade-off. On one hand, I knew my shoulders and transfers were my lifeline to independence, and I wanted to protect them for the long haul. On the other hand, I had a burning desire to move—push hard on back roads, climb mountains, ski, and test my limits.

I made a conscious decision to accept some risk to my shoulders in exchange for the joy and mental health benefits of those experiences. I’m glad I did. But I did not make those choices because I believed I could “out‑exercise” my injury or burn my way back to metabolic normal. I used exercise as recreation and therapy for my mind, not as my primary metabolic tool.

Even now, I’m reminded of the cost. I’ve had my share of shoulder pain. Recently, I tore one of my biceps tendons during a simple transfer from the couch to my chair, and I still feel a twinge when I reach for a light switch. I don’t share that to scare you, but to be honest about the trade‑offs I’ve lived with.

I want to directly acknowledge those of you with higher‑level injuries and more limited — or no — use of your arms. Compared to paraplegia, the ability to “exercise” in the traditional sense is often even more restricted, if not completely. That can feel discouraging if you’ve been told that exercise is the main path to metabolic health. My goal in this series is to show you that your most powerful lever for metabolic health is still very much available to you—and it’s not hours on an arm crank.

FES and NMES Still Matter—Even If They Don’t “Burn Enough”

Given these constraints, it might be tempting to dismiss FES cycling or NMES resistance training as “nice but not worth it” because they cannot single‑handedly close the caloric gap. That would be a mistake.

What the FES and NMES data show is that these tools:

• Improve glucose handling and insulin sensitivity, with lower glucose and insulin during oral glucose tolerance tests and reductions in inflammatory markers like IL‑6, TNF‑α, and CRP after structured FES programs.

• Increase muscle mass and shift fiber composition, with studies from Sanna, Farkas, Fenton, Gorgey, and others showing meaningful hypertrophy and body‑composition changes in paralyzed limbs.

• Improve cardiocirculatory and ventilatory function, with meta‑analyses (like Frazão’s) demonstrating clinically important gains in metabolic and cardiorespiratory variables.

• Boost energy expenditure beyond sitting, especially when NMES protocols are optimized by recruiting more muscle and shortening rest periods.

Hybrid strategies (arm ergometry plus FES) roughly double oxygen consumption compared to FES alone, reaching 5–7 kcal/min in paraplegia and 3–5 kcal/min in tetraplegia. So the case for FES and NMES is not that they solve the energy balance equation. It is that they help rebuild the metabolic machinery—muscle, bone, vascular health, insulin sensitivity—that you need regardless of your calorie budget.

How The Guidelines Are Quietly Shifting—and Why Diet Must Be The Primary Lever

The most recent guidelines are starting to reflect this reality. The American College of Sports Medicine’s 2025 consensus statement notes that people with disabilities, including SCI, have 15–50% lower cardiorespiratory fitness than their able‑bodied peers even when activity levels are matched, and that substantial health benefits can arise from exercise doses below 150 minutes per week. SCI‑specific recommendations endorsed by ACSM and the American Spinal Injury Association no longer anchor exercise prescriptions to hard kilocalorie targets.

Instead, they focus on achievable doses—like 20 minutes of moderate‑to‑vigorous aerobic exercise twice per week, progressing toward 30 minutes three times per week, plus strength training twice per week. They acknowledging that more may be aspirational for many. Stillman and colleagues go further and state that 150 minutes of exercise per week is unlikely to be sufficient to restore energy balance in SCI because of obligatory sarcopenia and osteopenia.

All of this points toward a new hierarchy for cardiometabolic health in complete SCI:

1. Diet and nutrition as primary lever. Because resting and activity‑related energy expenditure are both constrained, diet and nutrition have to do the heavy lifting for metabolic health. I don’t subscribe to a simple “calories in, calories out” model. The type of calories, the balance of protein, fat, and carbohydrate, and how they affect hormones and appetite matter a great deal—especially after SCI, when your muscle mass and metabolic flexibility are constrained.

2. FES, NMES, and hybrid exercise for metabolic quality. These tools are essential to preserve and rebuild muscle, maintain bone, improve insulin sensitivity, and support cardiovascular health—even when their raw caloric output is modest.

3. Upper‑extremity exercise, with a strict shoulder budget. Arm ergometry, wheelchair propulsion, and resistance training for the upper body are still important, but every extra hour spent chasing calories is an hour withdrawn from your shoulder “bank account.”

Higher-Level Tetraplegics

If you’re reading this with very limited ability to exercise—especially with higher‑level tetraplegia—I want you to hear this clearly: you still have an incredibly powerful lever to improve metabolic health, and in my view it is more powerful than exercise alone. That lever is how and what you eat. A unique challenge for our population is food preparation and access to healthy options.

Finally…

You can stop trying to out‑exercise a physiology that was fundamentally altered by your injury. Instead, you can invest in realistic, high‑yield levers—nutrition, carefully dosed FES/NMES, and shoulder‑protective activity—that will matter far more for your long‑term health and independence.

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This is one article in the numbered Spinal Cord Thrive series. The posts stand alone, but because they build on each other, many readers find it most helpful to read them in order from “Thrive 1” onward.

Glen House, MD

This can be confusing and frustrating because:

• Your BMI might say “normal” or “just a little overweight.”

• Your belly might look bigger, especially when you’re sitting.

• Your lab work might show rising blood sugar, cholesterol, or blood pressure.

Let’s unpack why that happens—and what to pay attention to instead.

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What is BMI, in Plain English?

BMI (body mass index) is a simple formula:

> BMI = weight (kg) ÷ height (m)²

Most online calculators are easy to use—just search “BMI calculator,” plug in your height and weight, and it will do the math for you and give you a number, then classify it:

BMI: Able-Bodied

• Normal: 18.5–24.9

• Overweight: 25–29.9

• Obese: 30 or higher

This works “okay” for large groups of people without SCI. It does not work well for people with spinal cord injury, because your body changes in ways BMI cannot see.

After SCI:

• You lose muscle below the level of injury.

• You often gain fat, especially around the belly.

• Your metabolism slows down.

So two people can have the same BMI of 24:

• One is mostly muscle with some fat.

• The other (with SCI) has less muscle and much more fat.

On paper, they look the same. In reality, they’re not.

What BMI Really Means in SCI

Studies that compared BMI to actual body fat (using DEXA scans) found that BMI often “underestimates” how much fat people with SCI carry.

A few key points:

1. At the same BMI, people with SCI can have 8–10% more body fat than those without SCI.

2. In one study, using the usual BMI cutoff of 30 for “obesity” missed almost 74% of people with SCI who truly had obesity by body fat and inflammation markers.

3. Researchers concluded that people with chronic SCI and BMI above about 22 should already be considered at high risk for obesity‑related problems.

Because of this, many experts now suggest “lower cutoffs” for SCI, for example:

• Recommended range: BMI below about 22

• Overweight: 22–24.9

• Obese / high‑risk: 25 or higher

That doesn’t mean everyone above 22 “has obesity.” It means: above that range, we should start asking more questions and looking deeper.

DEXA: The Closest Thing To a “Truth Detector”

If I could pick one test to answer “how much fat do I have, and how much muscle?”, it would be a DEXA scan.

A DEXA scan is a low‑radiation X‑ray test that measures how much of your body is bone, muscle, and fat. You usually lie flat on a padded, open table while a scanner moves over you—there’s no tunnel like an MRI and it’s quick and painless.

DEXA Scan:

• Separates bone, muscle (lean tissue), and fat.

• Shows how much fat is in your trunk vs arms and legs.

• Helps identify “sarcopenic obesity”—high fat and low muscle at the same time, which is very common after SCI.

Guidelines and reviews consistently point to DEXA as the best way we currently have to measure body composition in SCI. The downside is access and cost; not everyone can get one.

So BMI and waist size are still used as quick screening tools. But we have to interpret them differently in SCI. What About Waist Size and “belly fat”?

Waist circumference (belly size) is often used as a simple way to estimate harmful “visceral fat”—the fat packed around the organs that drives diabetes and heart disease. In studies of people without SCI, a bigger waist generally means higher risk. In SCI, that is partly true—but there’s a big catch.

Many people with higher‑level injuries have a protruding abdomen that makes the waist measure larger than their actual fat stores, while people with lower‑level paraplegia (around T10 and below) often keep more normal abdominal muscle tone and a firmer trunk, so their waist measurements and body shape behave much more like those of the able‑bodied population and standard waist‑based risk rules tend to apply more reliably to them than to those with higher injuries.After SCI, especially with mid‑thoracic (T1–T6) and higher injuries and in cervical injuries/tetraplegia:

• The abdominal wall is weak or flaccid.

• Trunk control is limited.

• Sitting posture often collapses forward.

That changes how your belly “looks” and how it “measures”, even if your actual fat doesn’t change.

From my own experience and from the research:

- Sitting in a wheelchair, the belly can “pooch” forward like a soft bag.

- Lying flat on your back, the belly can look much flatter because gravity pulls the organs backward.

- If you measure your waist sitting and then lying down, you can get “very different numbers” with no real change in visceral fat.

So when someone wraps a tape measure around your waist:

- The number they get depends on “position” (sitting vs lying)

- How upright you are

- Where they place the tape

- How much abdominal muscle control you have

This makes a single waist measurement—and any hard cutoff—much less reliable in SCI.

So What Should You Actually Do?

Here’s how I’d think about it if you’re living with SCI.

1. Use BMI as a rough “directional” tool

- Don’t panic about a single number, but know that for SCI, concern often starts above BMI 22–25, not 30, so you need to be aware of potential problems much earlier than you would without a spinal cord injury.

- If your BMI is creeping up year after year, especially into the mid‑20s or higher, that deserves attention, and the best way to make sense of it is to use yourself as the control—get a baseline as early as you can after injury (or now, if it’s been years) and track changes over time, because it’s never too late to start.

2. Treat waist measurements carefully

- Understand how your waist is being measured—seated or lying, and at what location.

- Try to have it measured the same way every time, so you can at least track change.

- Focus more on trends over time (is it slowly increasing?) than on a single cutoff.

3. Ask about body composition (if possible)

- If you can access it through your healthcare system, I strongly recommend asking your physician to order a DEXA scan, getting a baseline body composition as soon as possible after your injury (or now, if it’s been years), and then repeating it periodically so you and your team can track real changes in muscle and fat over time rather than relying on BMI alone.

- If not available, ask if there are other ways they can estimate your body fat and muscle (e.g., bioimpedance, or SCI‑specific equations).

4. Look beyond the scale and tape

No matter what the BMI or waist says, it’s essential to check:

- Blood sugar (fasting glucose, HbA1c)

- Cholesterol and triglycerides

- Blood pressure

- Liver enzymes (which can hint at fatty liver)

Clinical guidelines for SCI emphasize that cardiometabolic risk (diabetes, heart disease, stroke) is often as high or higher than in people without SCI, and that it is driven by all the features of Paralysis Metabolic Dysfunction (described in earlier newsletters)—not just by BMI.

My Bottom Line For You

If you have spinal cord injury:

• A “normal” BMI does not guarantee a healthy amount of body fat.

• A big belly when sitting doesn’t always mean you suddenly gained a ton of fat—it can also be weak abdominal muscles and posture.

• BMI and waist size are starting points, not final answers.

What matters most is:

• How much fat and muscle you truly have (body composition),

• Where that fat is stored (especially around the organs), and

• What your blood work and blood pressure say about your cardiometabolic health.

Use the numbers you get (weight, BMI, waist) as prompts to ask better questions—not as labels that define you. In upcoming Spinal Cord Thrive posts, I’ll walk you through my own journey—how I lost weight, reduced visceral fat after a C7 injury, and the specific methods I used so you can see how these principles play out in real life.

Glen House, MD

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This article by Farkas and colleagues is summarize below.

What Were They Looking At?

This paper tackles a big, often overlooked question: why do so many people with spinal cord injury (SCI) develop “cardiometabolic” problems—things like weight gain, unhealthy cholesterol, high blood pressure, and insulin resistance—and what can we do about it?

The authors pull together recent research to explain how these issues develop specifically in SCI, how they’re best measured, and how we should be screening and managing them over time.

Key Idea: “Neurogenic” Obesity After SCI

After an SCI, your body changes in ways that are very different from someone who gains weight without paralysis:

• You lose a lot of muscle below the level of injury.

• Your daily calorie burn drops sharply, even if your scale weight doesn’t change much.

• Hormonal and nervous system changes make it easier to store fat and harder to burn it.

The authors call this pattern “neurogenic obesity.” On a regular BMI ( Body Mass Index) chart, you might look only “overweight” or even “normal,” but your actual body fat percentage and deep belly fat can be very high. That hidden fat is what drives much of the risk.

What Did They Find?

In plain terms, three main messages come through:

1. Cardiometabolic Problems Are Common and Serious In SCI.

People with SCI have higher rates of obesity, abnormal lipids (high triglycerides, low HDL), high blood pressure, and abnormal glucose control than people without SCI. These combine into “cardiometabolic syndrome,” which carries a heart‑disease risk similar to having type 2 diabetes.

2. Standard Cutoffs (like BMI 30) Miss a Lot of Risk.

In SCI, obesity starts at much lower BMI values than in the general population. A BMI over about 22 can already mean a high body‑fat percentage and higher cardiometabolic risk. Waist measurements and direct body‑fat measures (when available) give a clearer picture than BMI alone.

3. Visceral Fat and Chronic Inflammation Are the Real Villains.

Extra fat, especially deep belly (visceral) fat, becomes “toxic” tissue: it releases inflammatory chemicals and free fatty acids that:

• Worsen insulin resistance

• Disturb cholesterol and triglyceride levels

• Raise blood pressure

• Promote plaque in arteries and increase heart‑attack and stroke risk

This can be happening even if the scale doesn’t look alarming by standard charts.

How should SCI cardiometabolic risk be diagnosed?

The authors argue that SCI needs its own lens, not just general‑population rules. That means:

• Using lower BMI thresholds (around > 22) to flag obesity in SCI.

• Paying close attention to waist size and, when possible, imaging or DXA to identify visceral fat.

• Screening regularly for:

1. Lipids (triglycerides, HDL, LDL, total cholesterol)

2. Blood pressure

3. Fasting glucose and markers of insulin resistance

They highlight existing SCI‑specific guidance (such as from Paralyzed Veterans of America) that recommends routine annual screening, starting early and continuing across the lifespan.

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What Can Actually Be Done?

The encouraging news: these risks are modifiable, even with paralysis.

The paper emphasizes:

1. Exercise adapted to SCI

• Functional electrical stimulation (FES) cycling to recruit leg muscles

• Arm‑based aerobic exercise (hand‑cycle, arm ergometer)

• Resistance or circuit training for upper body

These approaches have been shown to improve triglycerides and HDL, insulin sensitivity, body composition, and sometimes blood pressure.

2. Heart‑healthy, energy‑aware nutrition

Because calorie needs are lower after SCI, “normal” eating can easily overshoot. The authors support:

• Emphasizing vegetables, fruits, whole grains/legumes, and lean protein

• Cutting back on added sugars, refined carbs, saturated fat, and excess sodium

• Matching intake to your lower energy expenditure to avoid slow, steady fat gain

They note that combined diet‑plus‑exercise studies are still limited, but the available data are consistent: people with SCI can improve their cardiometabolic profile with structured lifestyle changes.

Note: Although these authors base many of their targets on data from the general population, they explicitly apply these recommendations to people with spinal cord injury. In later sections, I suggest alternative targets in selected areas and explain the rationale and observed outcomes.

What This Means If You Live With SCI?

Here’s how this study might translate into real life decisions:

1. Don’t rely on the standard BMI chart.

If you have SCI, a BMI in the low‑ or mid‑20s might already represent unhealthy body fat. Talk with your doctor or rehab team about using SCI‑specific cutoffs and, if possible, getting body‑composition or visceral‑fat measurements.

2. Treat screening as essential maintenance, not optional.

Ask that your yearly labs and clinic visits include:

• Blood pressure (with attention to autonomic issues)

• Fasting lipid panel

• Glucose/diabetes screening

This is about catching problems early, when they’re easier to manage.

3. Focus on visceral fat, not just the scale.

Small changes in waist size or body‑fat distribution can matter more than a few pounds up or down on the scale.

4. Lean into adapted exercise.

If you have access, FES‑cycling plus arm or chair‑based aerobic exercise can be powerful tools. If you don’t, any safe, regular upper‑body activity is still better than none.

5. Dial in nutrition for an SCI metabolism.

Think: fewer “empty” calories, more nutrient‑dense foods, and portions that match your reduced energy needs.

In short, the paper reframes cardiometabolic disease in SCI as both more common and more preventable than many people realize: a major long‑term threat, but one that can be meaningfully reduced with the right screening and lifestyle strategies tailored to life after spinal cord injury.

Glen House, MD

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If you’re living with spinal cord injury, you’ve already had more than enough taken from you. The last thing you need is another doom‑and‑gloom lecture about all the ways your body is “broken.”

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That’s not what this is.

When you understand the biology, the recommendations stop sounding like vague clichés (“eat less, exercise more”) and start making sense in a very specific, paralysis‑focused way. There are ways to lower inflammation, improve insulin sensitivity, rebuild some metabolic muscle, and reduce long‑term risk. And in future Spinal Cord Thrive newsletters, I’m going to show you those strategies—nutrition, stimulation, movement, medications, and more—over and over, from different angles, so you’re not just told you’re at higher risk; you’re shown how to push back and improve health.

What I’m doing is laying out a clear map of what’s happening under the surface—why your labs look the way they do, why your risk profile changes, and why your body can feel so different. When you understand the biology, the steps to push back become more logical, more targeted, and frankly, more hopeful. There are ways to bend this trajectory: to lower inflammation, improve insulin sensitivity, rebuild some metabolic muscle, and reduce long‑term risk.

In upcoming Spinal Cord Thrive newsletters I’ll share what I know and my personal experience. I’ll walk through those strategies repeatedly—nutrition, stimulation, supplements, medications, and more—so you’re not just told “you’re at higher risk,” you’re shown how to fight back.

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This is a key point.

Chronic inflammation after spinal cord injury is not just a bystander—it is tightly wired into a metabolic dysfunction that deserves its own name: Paralysis Metabolic Dysfunction.

How Chronic Inflammation and Metabolism Intersect After SCI

When you live with chronic SCI, your body composition and your immune system change in ways that strongly favor insulin resistance. Within weeks to months, there is a major loss of lean mass (especially in paralyzed legs), a gain in fat mass, and a marked increase in fat stored inside muscle (intramuscular fat), all of which are classic drivers of poor glucose handling.

Key patterns that show up again and again in SCI cohorts:

• Glucose intolerance and insulin resistance are common in people with chronic SCI.

• Abnormal oral glucose tolerance tests are more common in people with SCI than in age-matched able-bodied controls.

• Fasting glucose and Hemoglobin A1C may still appear normal, but abnormal oral glucose tolerance tests (OGTT) are still common.

• Increased fat mass and decreased muscle mass, along with increased intramuscular fat, contribute to impaired glucose disposal after SCI.

On top of the changes in muscle and overall body fat, there is a chronic “inflammation signal” running through the body. That signal shows up in the blood as higher levels of markers like CRP, IL‑6, and TNF‑α (lab markers your doctor might order to measure inflammation). You can think of these molecules as text messages the immune system sends when it thinks there is ongoing trouble. In chronic SCI, a major source of those messages is neurogenic obesity—especially the deep visceral fat that tends to build up around the organs in the abdomen. That visceral adipose tissue behaves less like passive storage and more like an irritated gland, constantly secreting inflammatory signals into the bloodstream.

Those inflammatory messages don’t just sit there; they get in the way of how insulin works. Normally, insulin is the hormone that tells muscle and liver cells, “Hey, there’s sugar in the blood—pull it in and use it or store it.” When CRP, IL‑6, TNF‑α and similar signals are chronically elevated, they interfere with that conversation. The cells “hear” insulin less clearly, so they don’t pull in glucose as effectively, and the pancreas has to pump out more insulin to get the same job done.

We see this in laboratory studies: people with SCI who have higher levels of these inflammatory markers (CRP, IL‑6, TNF‑α) also tend to have higher fasting insulin levels, which is a red flag for insulin resistance. And when SCI is combined with neurogenic obesity and extra visceral fat, those inflammatory markers are often even higher, which pushes insulin resistance further. So the same cytokines that tell us there is “invisible fire” in the body are also turning down the volume on insulin’s message to muscle and liver—and a big part of that firewood is visceral adipose tissue in paralysis.

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Why I frame this as “Paralysis Metabolic Dysfunction”

If you put all of this together—severe muscle loss, neurogenic obesity, intramuscular fat, chronic systemic inflammation, and a high prevalence of insulin resistance and chronically elevated glucose—it stops looking like ordinary metabolic syndrome that just happens to occur in a person with SCI. It looks like a distinct, paralysis‑driven metabolic disease process.

Some distinguishing features:

1. Early onset and high prevalence: Glucose intolerance, insulin resistance, and abnormal lipids (“cholesterol”) appear earlier and more frequently than in able‑bodied peers.

2. Body composition pattern: Profound lower‑extremity muscle atrophy with disproportionate visceral and intramuscular fat, despite “normal” or even only mildly elevated BMI in some cases.

3. Neuro‑immune link: Metabolic changes are not just a product of lifestyle and diet; they are tightly coupled to neurogenic changes in muscle, autonomic dysfunction, and chronic inflammation.

That is why I argue we should name it and treat it as its own entity—Paralysis Metabolic Dysfunction—rather than letting it hide under generic labels like “metabolic syndrome” or “type 2 diabetes.”

By “Paralysis Metabolic Dysfunction,” I mean the specific cluster of muscle loss, lack of contraction, neurogenic obesity, intramuscular and visceral fat, chronic inflammation, and insulin resistance that is driven directly by paralysis—not just lifestyle. I’ve walked through each of these components in earlier Spinal Cord Thrive articles, so if any of these terms feels new, you can refer back to those previous newsletters for a deeper dive.

The Vicious Cycle: Fat, Inflammation, Insulin Resistance

Once this process is set in motion, it becomes self‑reinforcing:

• Loss of muscle and reduced activity diminish the body’s main glucose sink.

• More calories are diverted into fat storage, including visceral and intramuscular fat.

• Adipose tissue—especially around the organs—acts like an endocrine organ, secreting pro‑inflammatory adipokines (including IL‑6 and TNF‑α).

• Those cytokines further impair insulin signaling and push CRP higher, deepening systemic inflammation.

• The resulting insulin resistance pushes the pancreas to make more insulin, which favors additional fat storage and liver lipid accumulation.

In SCI, this cycle is not just lifestyle‑driven; it is structurally wired into the consequences of paralysis itself.

What This Means For You In Practical Terms

If you live with SCI, you should assume you are at significantly higher risk of metabolic dysfunction—even if your fasting glucose or hemoglobin A1c still look “okay” on paper. That doesn’t mean it is inevitable, but it does mean we need to be more proactive and more nuanced.

Some practical implications that I’ll expand on in dedicated pieces:

• We should be screening earlier and more aggressively for insulin resistance (for example with oral glucose tolerance testing, fasting insulin, and triglyceride‑HDL patterns), not just waiting for frank diabetes to appear.

• Interventions that build or preserve muscle (e.g., carefully programmed functional electrical stimulation, resistance work where feasible) are not “optional extras”—they are frontline metabolic therapies in paralysis.

• Nutrition strategies that lower the total inflammatory load, reduce visceral and intramuscular fat, and smooth out glucose and insulin spikes can meaningfully push back against this paralysis‑driven metabolic tide.

I’m genuinely excited about where this is headed. In upcoming Spinal Cord Thrive articles, I’ll dig deeper into how chronic inflammation, autonomic disruption, and muscle biology after SCI intersect with GLUT4, insulin signaling, and ectopic fat—and then begin sharing the strategies I’ve been uncovering to push those systems in a healthier direction. I’m spending this early series laying the groundwork so that when we get to the “what to do about it” phase, the *why* behind each step is crystal clear and you can apply it with confidence.

Glen House, MD (C7 “metabolically healthy” complete SCI)

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Insulin resistance after spinal cord injury is not just a lab value problem. It’s a communication problem between insulin, its receptor, and the machinery that is supposed to move GLUT4 to the surface and let glucose in. The hormone is still speaking, but below the level of injury, the muscle has stopped listening clearly—and over time, that broken conversation reshapes your entire metabolic landscape.

In an earlier newsletter (Thrive 2), I’ve talked about insulin as a key, the insulin receptor as a lock, and GLUT4 as the doors that let sugar into your muscle. That framing still works—but today I want to zoom in one level and ask a sharper question:

What exactly goes wrong in that key → lock → door system after spinal cord injury?

Because if we’re serious about preventing diabetes, heart disease, and silent weight gain after SCI, we can’t just say “insulin resistance” and move on. We need to understand where the pathway is failing and how what can be done.

Step 1: Insulin Rings the Doorbell

When you eat and your blood sugar rises, your pancreas releases insulin into the bloodstream. Those insulin molecules travel through your circulation and bind to insulin receptors on the surface of your muscle cells—you can think of each receptor as a doorbell on the cell membrane.

In a Metabolically Healthy Person, The Sequence Looks Like This:

• Insulin arrives and presses the doorbell (binds the receptor).

• The receptor sends a signal inside the cell to a helper protein called IRS‑1.

• IRS‑1 passes the message to PI3K.

• PI3K activates Akt (also called protein kinase B).

You don’t need to remember the acronyms. The key idea is that this IRS‑1 → PI3K → Akt chain is the cell’s internal “Yes, open the doors now” command—the same core pathway that is impaired in type 2 diabetes. It’s what turns a molecule knocking at the surface into actual glucose entry.

When that relay is strong, a modest amount of insulin rings the bell, the message is loud and clear, and muscle cells bring glucose in quickly and quietly. Blood sugar comes down with minimal insulin and minimal drama.

Step 2: After SCI, the Person Inside Stops Opening the Door

Most GLUT4 proteins—the doors that let glucose into muscle—are not sitting on the surface all the time. They live inside the cell in little storage packages called vesicles, waiting for a signal to move.

Here’s Where the House Analogy Helps:

1. Insulin at the front step is the visitor.

2. The insulin receptor is the doorbell.

3. IRS‑1, PI3K, and Akt are the person inside who hears the bell.

4. GLUT4 is the actual door they open.

In a Healthy Muscle:

1. The bell rings.

2. The person inside hears it clearly, stands up, walks to the door.

3. They open the door wide—GLUT4 moves to the surface, and glucose walks in.

After Spinal Cord Injury:

Below the level of the lesion, the problem changes in a way that looks very similar to type 2 diabetes-like pattern—but with its own twist.

The bell may still be ringing, but the person inside barely hears it or doesn’t bother to get up: the IRS‑1/PI3K/Akt signal is weak. Sometimes they crack the door open; sometimes they don’t open the door at all.

From the outside, what we measure is classic insulin resistance: higher insulin levels are required to move the same amount of glucose. But underneath, the story is more specific. The message from receptor to GLUT4 is breaking down at the post‑receptor level—after the key has already fit the lock.

Putting the Pieces Together: A Broken Conversation That Looks Like Diabetes

If we combine these human findings with what we know about insulin signaling in skeletal muscle more broadly, the story comes into focus:

1. The Front End (Receptor and Early Signaling):

In type 2 diabetes, chronic inflammation and excess lipid by‑products drive abnormal phosphorylation of IRS proteins and reduce PI3K and Akt activation, which directly blunts GLUT4 translocation (movement to the muscle membrane surface). After SCI, we see a similar picture: insulin is present and can bind, but it takes more of it to move the same amount of glucose (ring or knock louder), which is exactly what you’d expect if the IRS‑1/PI3K/Akt relay is blunted.

2. The Back End (GLUT4 Content and Trafficking):

In human SCI muscle, there are fewer GLUT4 doors—consistent with lower glucose uptake and storage capacity. That suggests not only a weaker signal to move GLUT4, but also a reduced inventory of GLUT4 to move in the first place.

In “House” Terms:

The bell still works.

The person inside is half‑asleep and often ignores it.

And over time, the homeowner is slow to open the door or doesn’t open it at all.

From the outside, all you see is that the house rarely opens up for deliveries. Glucose stays in the bloodstream longer. The pancreas works harder. Insulin levels remain high. Fat storage becomes easier and more centralized. Cardiometabolic risk climbs.

This is one of the core mechanisms behind what I call Paralysis Metabolic Dysfunction—a post‑receptor, diabetes‑like signaling problem layered onto profound muscle loss and central obesity.

Why This Changes How We Think About Treatment

Once you see insulin resistance after SCI as a broken conversation between insulin, its receptor, and GLUT4, the path forward becomes more strategic. We’re not just trying to “get glucose in”; we’re trying to reroute and repair signaling.

1. Nutrition: The Primary Lever

Diet and nutrition are the single most powerful levers you have. Thoughtful nutrition can completely change your metabolic trajectory after SCI.

By moderating the size and speed of glucose spikes, you reduce how hard insulin has to push on that damaged IRS‑1/PI3K/Akt pathway. At the same time, specific dietary patterns can engage other pathways—fat oxidation, ketone metabolism, mitochondrial efficiency—that help control blood sugar and inflammation without relying solely on insulin’s main relay. In future newsletters, I’ll go much deeper into this science and show actual outcome data, but the bottom line is simple: nutrition is where you can move the needle the most.

2. FES: Rebuilding Part Of The Signal

Functional electrical stimulation is the second major lever. Muscle contractions triggered by FES can partially restore and strengthen pieces of the IRS‑1/PI3K/Akt pathway and improve GLUT4 movement in paralyzed muscle.

The catch is that this isn’t a one‑and‑done intervention. The benefits depend on repetition. To maintain gains in insulin sensitivity and glucose handling, FES needs to be used regularly—typically several times per week—just like exercise in someone without SCI. Think of it as physical therapy for your insulin signaling: helpful, but only if you keep showing up.

3. Medications: Future Tools, Specific Targets

Finally, medications—present and future—may play an important role. Some drugs improve insulin sensitivity, others modify appetite and body weight, and newer agents may more directly influence muscle metabolism.

The key will be using these tools with a clear target in mind: not just chasing a “better” number, but supporting the underlying biology we’ve been talking about—improving how muscle listens to insulin, uses alternative metabolic pathways, and brings GLUT4 to the surface. As the science evolves, I’ll cover which medications make sense in the context of SCI and which ones may just be cosmetic fixes for the lab report.

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Sources

1. Cheng RD, Ren W, Sun P, et al. Spinal cord injury causes insulin resistance associated with PI3K signaling pathway in hypothalamus. Neurochem Int. 2020;140:104839. doi:10.1016/j.neuint.2020.104839.
   

2. Smith DL Jr, Yarar-Fisher C. Contributors to metabolic disease risk following spinal cord injury. Curr Phys Med Rehabil Rep. 2016;4(3):190-199. doi:10.1007/s40141-016-0124-7.
   

3. Li M, Chi X, Wang Y, Setrerrahmane S, Xie W, Xu H. Trends in insulin resistance: insights into mechanisms and therapeutic strategy. Signal Transduct Target Ther. 2022;7(1):206. doi:10.1038/s41392-022-01073-0.
   

4. Lavin DP, White MF, Brazil DP. IRS proteins and diabetic complications. Diabetologia. 2016;59(11):2280-2291. doi:10.1007/s00125-016-4072-7.
   

5. Cooney GJ, Thompson AL, Furler SM, Ye J, Kraegen EW. Skeletal muscle signaling associated with impaired glucose metabolism in obesity and type 2 diabetes. Diabetologia. 2002;45(4):509-518. doi:10.1007/s00125-001-0775-5.
   

6. Raymond J, Harmer AR, Temesi J, Van Kemenade CH. Glucose tolerance and physical activity level in people with spinal cord injury. Spinal Cord. 2010;48(7):591-596. doi:10.1038/sc.2009.180.
   

7. Boucher MJ, Wilson R, Noonan VK, et al. Effect of lower limb combined neuromuscular electrical stimulation and cycling on cardiometabolic health in people with spinal cord injury: a randomized controlled trial. J Neuroeng Rehabil. 2023;20(1):93. doi:10.1186/s12984-023-01195-w.

   Disclaimer:

   How I use AI: I use AI the way I once used human editors—to help with grammar, structure, and clarity. The ideas, clinical judgments, and stories are mine, drawn from 36 years of living with a spinal cord injury and 25 years in physical medicine and rehabilitation and spinal cord medicine. I write the content first, then use AI to tighten the language and improve flow, and I personally review and edit every piece before it is published. AI does not decide what I believe, what I recommend, or what I share; it just helps me say it more clearly and consistently.

   What this is (and isn’t): This newsletter is for education and reflection, not personal medical advice, diagnosis, or treatment. It cannot replace an individual evaluation or relationship with your own clinician, and you should never delay or ignore professional medical advice because of something you read here.
   

After a spinal cord injury, it can feel like you woke up in a new country with the same body but a completely different rulebook.

You still care about the same destination: living as long and as well as you possibly can. You still want to show up for the people you love, stay out of the hospital, and keep doing the things that make life feel like your life. But the path to that destination is now full of detours and steep climbs that most people never have to think about.

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If you were driving across the state, you’d want more than a vague “just head west and you’ll figure it out.” You’d want a real map. You’d want to know about the mountain pass that closes in the winter, the construction zone that will slow you down, and the hidden back road that might actually make the drive easier.

Your metabolism after spinal cord injury is no different.

Before we start talking about what to do and what not to do, we need a metabolic roadmap — a clear picture of the terrain we’re traveling through.

If you’ve been following along, you know I’ve already shared several posts laying the foundation for how spinal cord injury affects health and metabolism. My hope is that you’ve had a chance to read some of those. There will be many more to come as we build this roadmap together over time.

Why the roadmap comes first

Most health advice starts with the “to‑do list”:

• Eat this, not that.

• Exercise more.

• Lose weight.

• Sleep better.

You already know that script. You’ve probably heard it more times than you can count.

The problem is that after spinal cord injury, that script is incomplete at best and misleading at worst. It assumes a body that moves, burns energy, stores fat, and responds to hormones in ways that no longer apply to you.

If we skip straight to the recommendations without understanding what’s actually happening inside a paralyzed body, it’s like being told to “drive carefully” without anyone mentioning that your brakes only work half as well and the road is covered in black ice.

So in these ongoing newsletters, we’ll do things in a different order:

1. Map the terrain — what changes in metabolism after spinal cord injury.

2. Then travel through it — what might help, what probably doesn’t, and how I’ve tried to navigate it myself.

What the science has already given us

One thing I want to be absolutely clear about from the beginning: the scientific and academic community in spinal cord medicine has done an extraordinary job describing this terrain.

We are not guessing.

Researchers have:

• Measured how resting energy expenditure drops after SCI.

• Tracked how muscle disappears and fat redistributes into places it doesn’t belong.

• Shown how insulin resistance, inflammation, and mitochondrial dysfunction appear early and persist.

• Documented higher rates of cardiometabolic disease, even in people who don’t look overweight by standard measures.

A lot of my thinking comes directly from this work and from the long‑form essay I’ve written on these topics. In upcoming posts, I’ll take the key studies that shaped my understanding and break them down in plain language—what the researchers actually did, what they found, and how those findings fit into our metabolic roadmap.

My goal is for you to have real access to the knowledge base that has informed my own decisions, not just a filtered list of conclusions.

You may never read the original papers, and you shouldn’t have to. But you deserve to understand the core ideas they contain. My goal isn’t to replace that work—it’s to translate it into a functional map: a roadmap you can actually use.

Where I felt something was missing

I’ve lived with a C7 spinal cord injury for decades. I’ve also spent about 25 years as a physician working in spinal cord medicine. So I’ve seen this problem from both sides of the exam room.

On one hand, the science describing what goes wrong is remarkably detailed. On the other, the practical what do I do next? often feels vague, generic, or disconnected from the realities of living with paralysis.

At some point, I realized that the precision we had in describing the problem didn’t match the precision we were offering in the plan. That mismatch bothered me enough that I decided to treat my own metabolic health as a long‑term, serious project—not a side hobby or optional optimization, but a project that would shape the rest of my life.

For the last decade and a half, I have been deliberately, almost obsessively, trying to answer one question for myself:

Given everything we know about metabolism after spinal cord injury, what is the most rational, realistic strategy I can follow to change my trajectory?

This wasn’t an academic exercise. The stakes were—and are—personal and high. These choices have life‑altering consequences for me, and I’ve taken them accordingly. I haven’t been casually “trying a few things”; I’ve been intensely dedicated to following through.

From map to journey: what I’ll share

In this newsletter, I’m going to do something that’s both exciting and a little uncomfortable for me: make that process visible.

Here’s what you can expect over time:

• Clear explanations of the metabolic changes after SCI

  We’ll talk about what I think of as the core pieces of Paralysis Metabolic Dysfunction:

  • How fat redistributes, especially visceral and intramuscular fat.

  • What happens to muscle mass and contraction, and why that matters for energy expenditure.

  • How cellular signaling, insulin sensitivity, and inflammation shift in a paralyzed body.

I’ll keep the main text readable for anyone with an SCI, and occasionally add “deep dive” sections for those who want mechanistic or clinical details.

• Breaking down the key studies

  Many of the ideas I’ll share are grounded in specific studies that changed how I think about metabolism after SCI. I’ll highlight those papers, explain why they matter, and walk through what they actually showed—opening the “black box” of research so you can see the evidence that underlies the roadmap, not just the final recommendations.

• What I tried that didn’t work
  This part is important. I’ll discuss strategies that sounded good on paper but either did nothing, backfired, or weren’t sustainable in the real world. My goal isn’t to pretend I’ve always had the perfect plan, but to share the dead ends so you don’t have to repeat them.

• What’s worked surprisingly well so far
  I’ll walk through the approaches that produced meaningful changes in my labs, body composition, and how I feel. I’ll explain why I think they worked, where they fit into the roadmap, and what trade‑offs they required.

• Deliberate “good” and “bad” experiments
  At times, I’ll intentionally do things I know aren’t ideal—eat in ways that push my glucose and triglycerides up, change my activity routines, or alter other variables—just to show you what happens. Then I’ll show what it looks like to correct course.

This isn’t about perfection; it’s about making the invisible visible.

• Real data from my own life
  I plan to share past, current, and future lab results—along with context: what I was doing at the time, why I chose that strategy, and what I learned from it.

• An ongoing, open‑ended experiment
  I don’t have all the answers, and I won’t pretend to. What I can offer is a combination of:

  • Detailed science.

  • Lived experience in a paralyzed body.

  • A willingness to test, adjust, and be transparent about the outcomes in real time.

What I hope you take from this

You don’t have to become a scientist to care about your metabolism after spinal cord injury.

My hope is that as you read along, you will:

• See your own body differently.

• Understand why standard advice can feel like pushing a boulder uphill.

• Find a few ideas or frameworks to discuss with your care team.

• Feel less alone navigating a metabolic landscape that is genuinely more challenging than what most people face.

If you choose to follow this series, think of it as riding shotgun on my own metabolic road trip—wrong turns, course corrections, better routes, and all. I hope you gain something from this journey and enjoy the process.

Glen House, MD

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When you hear ‘muscle atrophy after spinal cord injury,’ it sounds simple: the muscles shrink. But under the microscope, something much more interesting—and more important—happens.”

The kind of muscle fibers you have changes, and that has huge consequences for long‑term metabolic health.

Before diving into the SCI data, let’s explain why it’s important to know the different types of muscle fibers, and how they act differently.

Muscle Fiber Types Made Simple!

You can think of your muscles as being built from different “athletes,” each with their own specialty. The main types in human skeletal muscle are:

Type I (oxidative) – lots of endurance, but less force

• Think of a marathon runner or long‑distance cyclist.

• These slow‑twitch fibers are great at using oxygen to make energy for hours.

• They don’t produce huge force, but they resist fatigue extremely well.

• In everyday life, they handle posture, prolonged standing, walking, and low‑intensity activity.
  

Type IIa (oxidative-glycolytic) – the 400–800 meter runner or soccer player (the hybrid)

• Has to be fast, repeat efforts, and not fall apart in the second half.

• These fast‑twitch, oxidative‑glycolytic fibers are the “all‑around athlete” fibers.

• They can generate good power and still use oxygen reasonably well, sitting between pure endurance and pure power.

• With different types of training, they can shift to behave more like Type I (more endurance) or more like Type IIx (more power).

Type IIx (glycolytic) – the 100-meter sprinter or Olympic weightlifter

• Lives in the first few seconds of effort: huge power, then fades quickly.

• These fast‑twitch, glycolytic fibers produce very high force and speed, but fatigue rapidly.

• They rely heavily on anaerobic (non‑oxygen) energy systems and have fewer mitochondria.

In a healthy, active person, the muscles have a mix of all three. That mix is part of why someone can walk all day, play a match, and still sprint for the bus if they have to.

After spinal cord injury, that balance changes dramatically.

What SCI Does to Fiber Types and Muscle Structure

With loss of nerve input and loading, paralyzed muscles don’t just shrink—they reorganize.

The slow‑to‑fast shift

• Early after injury (first weeks), the basic fiber‑type pattern is still relatively normal; slow and fast fibers are still there in a familiar mix.

• Over the next several months, especially between about 1 and 20 months post‑injury, slow Type I fibers start to “lose their identity,” and more hybrid fibers (Type IIa) appear that co‑express slow and fast proteins (a sign of active transformation).

• By several years post‑SCI, many muscles below the lesion are dominated by fast Type II fibers, especially IIx, with a near‑disappearance of pure Type I.

In everyday terms, your muscle fibers shift from a balanced team of marathon runners and versatile hybrids to mostly sprinters who tire quickly and aren’t good at steady‑state work.

Atrophy, fat, and structural damage

Alongside fiber‑type changes:

• Cross‑sectional area of leg and thigh muscles can drop to roughly half of normal within the first 6 months after a complete SCI.

• Biopsies show severely shrunken fibers, particularly in early months for Type II fibers, with Type I catching up later.

• Over time, connective tissue and fat creep into the muscle, especially intramuscular fat (fat inside the muscle), which further reduces the amount of actual contractile tissue.

• In chronic incomplete and complete injuries, imaging confirms ongoing declines in muscle density (more fat) and, in many people, continued loss of muscle area rather than a true plateau.

The result: smaller muscles, more fast‑twitch fibers, less endurance capacity, and more fat where muscle used to be.

Why This Matters for Energy, Blood Sugar, and Heart Health

Skeletal muscle is the body’s main “sink” for sugar from the bloodstream. When muscle mass is low and the remaining fibers are poor at using oxygen and storing glycogen efficiently, several things happen.

Less muscle, worse “quality”

• We simply have fewer fibers and less total tissue to take up glucose, especially after meals.

• The fibers we do have are biased toward fast glycolytic (Type IIx) behavior—great for short bursts, poor for long‑duration, fuel‑efficient work.

• Mitochondrial content and oxidative enzymes drop, so even at the cellular level, the machinery for burning fuel is significantly reduced.

• Intramuscular fat, particularly inside and around fibers, is associated with local insulin resistance—that is, the muscle stops responding properly to insulin’s signal to take up glucose.

Changes in muscle signaling and gene expression

At the molecular level, muscle after SCI shows:

• Altered insulin‑signaling pathways and reduced sensitivity, especially in higher‑level injuries (like tetraplegia), contributing to impaired glucose tolerance and higher insulin levels.

• Changes in AMPK (a key energy sensor) and shifts in gene expression that decrease oxidative and fat‑burning pathways and increase glycolytic and fat‑storing pathways.

• Chronic low‑grade inflammation and activation of metabolic pathways that promote muscle breakdown and fibrosis, instead of repair and healthy remodeling.

When you zoom out from the muscle to the whole person, this shows up as:

• Higher rates of glucose intolerance, insulin resistance, and type 2 diabetes.

• Unfavorable cholesterol profiles (low HDL, high triglycerides).

• Increased rates of metabolic syndrome and cardiovascular disease.

• An overall picture where SCI itself is now recognized as a major cardiometabolic risk condition, not just a mobility issue.

In other words, the fiber‑type shift and structural/metabolic changes in muscle are not just local changes in muscle—they are central drivers of systemic health problems after SCI.

The Hopeful Part: Muscle Is Still Hugely Trainable!

The good news is that paralyzed muscle, even years after injury, is not “dead tissue.” It remains surprisingly adaptable if you give it the right kind of stimulus.

Early electrical stimulation: keeping Type I and IIa alive

When electrical stimulation (ES) training is started in the acute phase (within weeks of injury):

• Regular ES sessions can largely prevent the sharp drop in Type I fibers and the large collapse in fiber cross‑sectional area.

• Type I fibers remain more common, fiber sizes stay much closer to baseline, and the progression toward a purely fast‑twitch, shrunken muscle is slowed dramatically.

In simple terms, activating the muscle early and often sends a strong signal to “stay more like a marathon‑runner fiber type” and “don’t shrink so much.”

ES and exercise in chronic SCI: rebuilding what’s left

Even in chronic SCI:

• ES‑based resistance training and FES‑cycling can grow paralyzed muscles (hypertrophy) over months, increasing muscle size (cross‑sectional area) and contractile capacity.

• Mitochondrial enzymes and oxidative capacity improve, shifting some fibers back toward a more oxidative, fatigue‑resistant profile.

• Molecular signaling related to insulin and glucose uptake (GLUT4 pathways) becomes more responsive after ES sessions.

• Whole‑body outcomes—like insulin sensitivity, blood lipids, and other cardiometabolic risk markers—often improve alongside muscle size and quality.

Training does not magically restore normal contraction and function, but it does change the muscle’s internal mechanisms: fewer signals for breakdown, more capacity to handle glucose and fats, better mitochondrial health.

Chronic injury with “late to the stimulation party” muscle

Even in more challenging situations:

In long‑standing chronic injuries, spastic activity seems to protect some fibers from complete degeneration, making them quite responsive to ES even many years post‑injury.

The key message: your muscle fiber mix and metabolism are modifiable variables, not fixed outcomes of your injury.

What This Means for Us: A Practical Reframe

Putting all of this together:

• After SCI, muscles shift from a balanced mix of Type I, IIa, and IIx to a smaller, more fat‑infiltrated muscle dominated by fast‑twitch IIx fibers. That shift drives reduced endurance, more fatigue, and worse metabolic efficiency.

• Changes in muscle mass, fiber type, mitochondria, and intramuscular fat create great difficulty with blood sugar control and cardiometabolic risk—your muscles are important tools for managing health, even if you cannot voluntarily move them.

• Early intervention with ES and, if possible (incomplete injuries), active exercise can preserve slow and hybrid fibers, reduce atrophy, and keep mitochondrial and metabolic function closer to “healthy settings.”

• In chronic SCI, ES‑based resistance training, FES‑cycling, and carefully planned exercise still offer real potential to build muscle, improve oxidative capacity, and enhance insulin signaling.

• Nutrition and careful management of cardiometabolic risk factors (cholesterol, blood pressure, blood glucose) are important—but they work even better when paired with strategies that directly load paralyzed muscle.

We didn’t choose our level of injury, but we do have some influence over what kind of muscle sits below the injury—how much of it you keep, what fiber types dominate, how many mitochondria it holds, how much fat infiltrates it, and how well it handles glucose and fats. Those choices, made over months and years through ES, nutrition, and lifestyle, are a big part of how you thrive with spinal cord injury.

Glen House, MD

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by J. Glen House, MD

This comprehensive review introduces and characterizes “Paralysis Metabolic Dysfunction” (PMD), a condition describing the cascade of metabolic alterations following spinal cord injury (SCI). A synthesis of current evidence reveals that individuals with SCI experience immediate and progressive metabolic dysregulation at the cellular level, profound skeletal muscle remodeling, and significant adipose tissue alterations, particularly within visceral depots. These interrelated physiological adaptations collectively disrupt systemic metabolic homeostasis, leading to widespread insulin resistance marked by impaired insulin receptor signaling and reduced GLUT4 translocation. Consequently, the risk of type 2 diabetes and cardiovascular disease increases two‑ to three‑fold compared to able-bodied populations. Nutritional and lifestyle interventions emerge at the forefront of therapeutic strategies, demonstrating capacity to restore metabolic flexibility, improve insulin sensitivity, and reduce cardiometabolic risk. Functional electrical stimulation (FES) further complements these efforts by enhancing glucose tolerance, muscle mass, and vascular health through activation of paralyzed muscle groups. This review underscores the critical importance of early recognition and interdisciplinary management of PMD to mitigate the substantial morbidity and mortality associated with post‑SCI metabolic deterioration.

Introduction to Paralysis Metabolic Dysfunction

Spinal cord injury (SCI) represents a catastrophic neurological condition affecting approximately 17,700 new individuals annually in the United States, with a prevalence of approximately 294,000 persons living with SCI-related disabilities.¹While the neurological consequences of SCI have been extensively studied, the profound metabolic alterations that occur following paralysis remain underappreciated in clinical practice, despite their significant impact on long-term health outcomes and quality of life. This review introduces the concept of “Paralysis Metabolic Dysfunction” (PMD) as a distinct clinical entity encompassing the constellation of metabolic abnormalities that develop acutely and progressively after SCI, ultimately increasing the risk for type 2 diabetes, cardiovascular disease, and premature mortality.² The recognition of PMD as a defined condition may enhance clinical awareness, facilitate earlier intervention, and improve research focus on this critical aspect of SCI care.

The metabolic consequences of SCI extend far beyond the obvious mobility limitations and include dramatic alterations in body composition, energy expenditure, glucose homeostasis, and lipid metabolism.³ These changes begin immediately following injury and evolve over time, creating a physiological environment that promotes insulin resistance, dyslipidemia, and systemic inflammation. Within the paralyzed regions, profound muscle atrophy and fiber-type shifts occur alongside increases in intramuscular adipose tissue, while systemic changes include increased visceral adiposity and altered adipokine profiles.^4,5 Together, these alterations create a perfect metabolic storm that dramatically increases cardiometabolic risk.

Current SCI management focuses predominantly on neurological recovery, prevention of secondary complications such as pressure injuries and urinary tract infections, and functional rehabilitation. However, the metabolic aspects of SCI often receive inadequate attention, potentially missing critical opportunities for intervention that could substantially impact long-term health outcomes. By conceptualizing these metabolic alterations as a defined syndrome---Paralysis Metabolic Dysfunction---the goal is to elevate awareness of these issues among healthcare providers and researchers working with SCI populations.

This review synthesizes current evidence regarding the pathophysiological mechanisms underlying PMD, its clinical manifestations and progression, associated complications, and potential therapeutic interventions. Through this comprehensive examination, the hope is to establish a foundation for improved clinical recognition, research focus, and targeted interventions for this significant but often overlooked aspect of SCI care.

Pathophysiology of Acute Metabolic Changes Following SCI

The metabolic consequences of spinal cord injury begin immediately following trauma, initiating a cascade of physiological alterations that lay the groundwork for long-term metabolic dysfunction. Within hours of injury, a profound neurogenic shock response disrupts sympathetic nervous system function, particularly in cervical and high thoracic injuries, leading to bradycardia, hypotension, and decreased systemic vascular resistance. This autonomic disruption has immediate metabolic implications, altering catecholamine levels and basal metabolic rate. Concurrently, a significant stress response triggers the release of counter-regulatory hormones including cortisol, glucagon, and catecholamines, which collectively promote hyperglycemia and initiate a catabolic state.⁶ These hormonal alterations directly impact glucose metabolism, creating a state of stress-induced hyperglycemia that can persist well beyond the acute injury phase.

Inflammatory processes initiated by the primary trauma contribute substantially to early metabolic disruption. The release of pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) from the injured spinal cord creates a systemic inflammatory environment that impairs insulin signaling pathways. Studies have demonstrated elevated circulating inflammatory markers persisting for weeks following injury, with TNF-α levels showing particular correlation with insulin resistance measures. This inflammatory milieu directly interferes with insulin receptor substrate (IRS) phosphorylation and downstream signaling, representing one of the earliest mechanisms of insulin resistance following SCI.^7,8,9,10 The inflammatory response also promotes muscle proteolysis, contributing to the rapid muscle atrophy observed in paralyzed limbs.¹¹

Energy expenditure undergoes dramatic alteration immediately following SCI, with studies documenting a 14-27% reduction in resting energy expenditure compared to pre-injury requirements.^12,13 This reduction stems from the loss of neural input to skeletal muscle below the level of injury, resulting in decreased muscle tone and metabolic activity. The immediate mismatch between energy intake and decreased expenditure creates a positive energy balance that, if not addressed, contributes to rapid adipose tissue accumulation. Meanwhile, the loss of normal loading forces and neuromuscular activation below the level of injury triggers rapid muscle atrophy, with studies documenting up to 40% reduction in cross-sectional area of affected muscles within the first month post-injury.¹⁴ This muscle loss represents not only a structural change but a critical metabolic alteration, as skeletal muscle serves as the primary site for insulin-stimulated glucose disposal.

Glucose metabolism shows early disruption following SCI, with several studies documenting impaired glucose tolerance and hyperinsulinemia in individuals with SCI, even in those without prior diabetes.^15,16 This rapid development of insulin resistance appears mediated by multiple pathways, including stress hormone elevation, inflammatory signaling, and the immediate reduction in muscle glucose utilization due to paralysis. The acute loss of contraction-mediated glucose uptake in paralyzed muscle---a pathway that normally operates independently of insulin---further compounds glucose dysregulation, as this mechanism typically accounts for approximately 70-80% of whole-body glucose disposal, as skeletal muscle is the principal site of glucose uptake during feeding and insulin‑stimulated states.¹⁷ These acute alterations in glucose homeostasis establish a foundation for the progressive metabolic dysfunction that characterizes the chronic phase of SCI.

Progressive Metabolic Alterations in Skeletal Muscle

The skeletal muscle undergoes profound structural and functional transformations following spinal cord injury, driving significant aspects of Paralysis Metabolic Dysfunction. Within the first months after injury, denervated muscles undergo a dramatic shift in fiber‑type composition, characterized by a conversion from slow‑twitch oxidative (Type I) fibers toward fast‑twitch glycolytic (Type II) fibers.¹⁸ This transformation fundamentally alters the metabolic capacity of affected muscles, reducing mitochondrial density, oxidative enzyme activity, and fatty acid oxidation potential. Studies utilizing muscle biopsies from individuals with chronic SCI have demonstrated up to a 90% predominance of Type II fibers in paralyzed muscles compared to a more balanced distribution in able-bodied controls.¹⁸ This fiber-type transition has profound implications for glucose metabolism, as Type II fibers exhibit lower insulin sensitivity and reduced capacity for glucose disposal compared to their Type I counterparts.

Concurrent with fiber-type transitions, paralyzed muscles experience progressive atrophy that continues well beyond the acute phase of injury. Research utilizing advanced imaging techniques has documented 30–50% reductions in muscle cross‑sectional area within the first months post‑injury, with ongoing atrophy occurring at a slower rate for years thereafter.¹⁶ This atrophy disproportionately affects Type I fibers, further exacerbating the shift toward a glycolytic phenotype. The loss of muscle mass directly impacts whole-body metabolism, as skeletal muscle serves as the primary tissue for insulin-stimulated glucose disposal and a major contributor to basal metabolic rate. Longitudinal studies have demonstrated strong correlations between the degree of muscle atrophy and the severity of glucose intolerance in individuals with SCI, highlighting the metabolic significance of these changes.¹⁷

A particularly concerning aspect of muscle transformation following SCI is the progressive infiltration of adipose tissue within and between muscle groups, termed intramuscular fat (IMF) and intermuscular fat, respectively. Using magnetic resonance imaging, it has been demonstrated that individuals with chronic spinal cord injury exhibit approximately a three‑ to four‑fold increase in intramuscular fat within paralyzed thigh muscles compared with able‑bodied controls, despite similar total mid‑thigh cross‑sectional area.¹⁹ This ectopic fat deposition creates a lipotoxic environment within skeletal muscle that contributes to insulin resistance through multiple mechanisms, including increased local production of inflammatory cytokines and accumulation of lipid intermediates such as diacylglycerols and ceramides.¹⁹ The close proximity of these lipid depots to myofibers permits local activation of stress and kinase pathways that impair insulin receptor substrate phosphorylation and downstream signaling, thereby promoting muscle‑specific insulin resistance that can precede and drive systemic metabolic dysfunction.²⁰

At the molecular level, significant alterations in insulin signaling pathways emerge within paralyzed muscles. Studies examining muscle biopsies from individuals with chronic SCI have demonstrated reduced expression and activation of insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase (PI3K)--key components of the insulin signaling cascade. Particularly notable is the reduction in glucose transporter type 4 (GLUT4) content and translocation efficiency in paralyzed muscle. GLUT4, the primary insulin-responsive glucose transporter in skeletal muscle, normally translocates from intracellular vesicles to the cell membrane in response to insulin stimulation and muscle contraction. In SCI, both the total GLUT4 content and its ability to translocate in response to insulin are compromised, significantly impairing glucose uptake capacity. The loss of contraction-mediated GLUT4 translocation represents a particularly important mechanism in SCI-related insulin resistance, as this pathway normally provides a substantial insulin-independent mechanism for glucose disposal during physical activity.²¹

Mitochondrial dysfunction emerges as another critical component of muscle‑related Paralysis Metabolic Dysfunction. Paralysis, unloading, and disruption of central nervous system communication after spinal cord injury rapidly disturb key regulators of mitochondrial health in skeletal muscle, including peroxisome proliferator‑activated receptor gamma coactivator 1‑alpha (PGC‑1α), leading to reductions in mitochondrial content and oxidative enzyme activity in paralyzed muscles.²² These mitochondrial alterations impair oxidative metabolism, contributing to reduced fatty acid oxidation, increased intramuscular lipid accumulation, and further compromise of insulin sensitivity, thereby establishing a vicious cycle in which mitochondrial dysfunction promotes lipid accumulation that in turn exacerbates mitochondrial impairment and insulin resistance.²³

Adipose Tissue Dysregulation and Inflammatory Consequences

Following spinal cord injury, dramatic alterations in adipose tissue distribution and function contribute substantially to the metabolic derangements characteristic of Paralysis Metabolic Dysfunction. A predominant feature is the accelerated accumulation of visceral adipose tissue (VAT), with studies utilizing dual‑energy X‑ray absorptiometry and computed tomography demonstrating VAT volumes approximately 30–60% higher in individuals with SCI compared to BMI‑ or waist‑matched able‑bodied controls.²⁴ This disproportionate visceral adiposity begins to develop early after injury and continues progressively, creating substantial cardiometabolic risk even in individuals whose BMI falls within the normal or only mildly elevated range.^24,25 The predilection for central adiposity appears to be related, at least in part, to injury‑induced alterations in sympathoadrenergic control of adipose tissue, with studies in people with SCI demonstrating impaired catecholamine responses and altered exercise‑induced lipolysis, as well as evidence that reduced sympathetic drive to abdominal depots may contribute to visceral fat accumulation.^25,26,27

In parallel with these quantitative changes, qualitative alterations in adipose tissue function emerge after SCI. Adipose tissue transitions from a primarily energy storage organ to a highly active endocrine tissue producing numerous adipokines that significantly impact systemic metabolism.²⁸ Analyses of circulating adipokines in chronic SCI consistently demonstrate dysregulated profiles, including elevated leptin levels and altered adiponectin–fat mass relationships, even after accounting for differences in body composition. Adiponectin, an insulin‑sensitizing adipokine that enhances glucose uptake and fatty acid oxidation, is inversely associated with visceral and total fat mass in individuals with SCI, and lower adiponectin levels within this population correlate with greater adiposity and adverse metabolic markers.²⁹ In parallel, hyperleptinemia develops alongside apparent central leptin resistance, blunting normal energy‑homeostasis signaling and contributing to persistent positive energy balance. These alterations in adipokine profiles directly modulate insulin sensitivity across multiple target tissues, particularly skeletal muscle and liver.³⁰

The expanded visceral adipose tissue serves as a persistent source of pro‑inflammatory cytokines, establishing a state of chronic low‑grade inflammation that further compromises insulin signaling.^28,29 Elevated circulating inflammatory markers, including C‑reactive protein (CRP), tumor necrosis factor‑alpha (TNF‑α), interleukin‑6 (IL‑6), and chemokines such as monocyte chemoattractant protein‑1 (MCP‑1), have been reported in individuals with chronic SCI, and higher levels of these biomarkers are associated with greater visceral adiposity and cardiometabolic risk.^8,31,32

This inflammatory environment impairs insulin signaling through multiple mechanisms, including inhibitory phosphorylation of insulin receptor substrates, activation of stress kinases such as c-Jun N-terminal kinase (JNK) and inhibitor of kappa B kinase (IKK), and induction of suppressor of cytokine signaling 3 (SOCS3). The resulting cytokine-mediated insulin resistance affects multiple tissues, creating a systemic metabolic dysfunction that extends beyond the directly denervated regions.³³

Beyond the expanded visceral compartment, individuals with SCI develop significant ectopic lipid deposition in non-adipose tissues, particularly liver and heart. Hepatic steatosis occurs at higher rates in SCI populations compared to able-bodied controls, with studies using magnetic resonance spectroscopy demonstrating increased intrahepatic lipid content that correlates strongly with insulin resistance measures.³⁰ This non-alcoholic fatty liver disease (NAFLD) spectrum represents not merely a consequence but an active contributor to metabolic dysfunction in SCI, as lipid-engorged hepatocytes produce inflammatory mediators, exhibit impaired insulin clearance, and increase hepatic glucose production through enhanced gluconeogenesis. Similarly, cardiac steatosis emerges as a concerning feature in chronic SCI, with potential implications for cardiac function and arrhythmia risk beyond the traditional cardiovascular risk factors.³⁴

The dysregulated adipose tissue metabolism following SCI creates a self‑perpetuating cycle of metabolic deterioration. Inflammatory mediators from expanded visceral adipose depots impair insulin signaling, producing insulin resistance that promotes compensatory hyperinsulinemia. Elevated insulin levels, in turn, enhance lipogenesis and acutely inhibit lipolysis in adipose tissue, facilitating further adipose expansion and perpetuating this vicious cycle.³⁵ Meanwhile, reduced physical activity and substantial muscle atrophy markedly decrease overall energy expenditure, and physiologic adaptations after SCI, including reduced resting energy expenditure relative to predicted values, further lower metabolic rate in response to injury.^36,37 This perfect storm of metabolic alterations creates a physiological environment highly conducive to ongoing adipose tissue expansion and progressive insulin resistance, ultimately driving the development of overt metabolic disorders in the chronic phase of SCI.

Progression to Metabolic Syndrome, Diabetes, and Cardiovascular Disease

The sum of metabolic changes following spinal cord injury creates a physiological environment highly conducive to the development of formal metabolic disease entities, with profound implications for long‑term health outcomes. Metabolic syndrome, characterized by central obesity, hypertension, dyslipidemia, and glucose intolerance, represents a common progression of Paralysis Metabolic Dysfunction, with reported prevalence in chronic SCI cohorts frequently in the 40–60% range and generally higher than in age‑matched able‑bodied populations.³⁸

Studies applying National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria generally report metabolic syndrome in roughly one‑quarter to over one‑half of individuals with chronic spinal cord injury, with higher prevalences in cohorts with more severe injuries and greater adiposity.³⁹

National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria are a standardized set of clinical cut‑points used to define metabolic syndrome and to guide cholesterol and cardiovascular risk management in adults.

For metabolic syndrome, ATP III defines it as having at least three of the following five abnormalities:

• Increased waist circumference (≥102 cm in men, ≥88 cm in women).

• Elevated triglycerides (≥150 mg/dl or on drug treatment).

• Reduced HDL cholesterol (<40 mg/dl in men, <50 mg/dl in women or on treatment).

• Elevated blood pressure (≥130/85 mmHg or on antihypertensives).

• Elevated fasting glucose ( ≥100 mg/dl, or on drug treatment).

The accelerated timeline reflects profound physiological alterations directly attributable to paralysis and neurogenic metabolic disruption, superimposed on reduced physical activity, rather than the more gradual, lifestyle‑mediated trajectory of metabolic syndrome typically observed in able‑bodied individuals.⁴⁰

This progression of PMD to diabetes stems from multiple mechanisms, including skeletal muscle atrophy and fiber‑type shifting toward fast glycolytic fibers, impaired skeletal‑muscle insulin signaling and glucose uptake, visceral adiposity, chronic inflammation, and reduced physical activity. The absence of neural‑mediated muscle contraction eliminates a major pathway for glucose disposal, while concomitant muscle atrophy and intramuscular fat accumulation reduce the quantity and quality of tissue available for insulin‑mediated glucose uptake.^41,42 Together, these alterations create a perfect storm for progressive glucose intolerance. The diagnosis of diabetes may be delayed in SCI populations because of an atypical presentation, with classic symptoms like polyuria altered by neurogenic bladder management and peripheral neuropathy unable to be identified because of sensory deficits from the spinal cord lesion.

Cardiovascular disease is the leading cause of mortality in chronic SCI, accounting for roughly 18–25% of deaths overall and approaching 46% among individuals who survive 30 years or more after injury.^44,45 Dyslipidemia is highly prevalent in chronic SCI, with studies reporting at least one lipid abnormality in roughly two‑thirds to three‑quarters of patients, most commonly markedly reduced high‑density lipoprotein cholesterol (HDL‑C), along with elevated triglycerides and adverse total cholesterol/HDL‑C ratios.⁴⁶ The cardiovascular risk profile in chronic SCI is characterized by a unique combination of traditional risk factors amplified by paralysis-specific pathophysiology.

The interface between autonomic dysfunction and metabolic alterations creates additional cardiovascular complexity in SCI. In individuals with injuries at or above T6, disruption of descending sympathetic pathways to the heart and vasculature produces a physiology characterized by relative parasympathetic dominance at rest but exaggerated, poorly regulated sympathetic responses to afferent stimuli due to loss of supraspinal control.⁴⁷ This autonomic dysregulation alters normal cardiovascular reflexes and contributes to unique cardiovascular risk beyond traditional metabolic factors. In parallel, cardiovascular deconditioning from severe physical inactivity and loss of the lower‑extremity muscle pump further impairs cardiac performance, with echocardiographic studies demonstrating progressive reductions in left ventricular mass, stroke volume, and cardiac output within months to years after SCI. ⁴⁸ These cardiac alterations, combined with the metabolic risk factors, create a particularly high-risk profile for cardiovascular disease in this population.

Within the framework of Paralysis Metabolic Dysfunction, cardiometabolic complications tend to emerge on an accelerated timeline, with insulin resistance and impaired glucose tolerance often detectable within the first months to few years after injury and a markedly increased incidence of type 2 diabetes and cardiovascular disease over the ensuing decade in susceptible individuals.⁴⁹ This accelerated timeline compared to the general population reflects the profound physiological disruptions directly attributable to paralysis rather than the gradual lifestyle-mediated changes typically observed in metabolic disease development. Recognition of this timeline provides critical opportunities for preventive intervention, particularly during the transition from acute to chronic SCI when many metabolic alterations remain potentially modifiable.

Clinical Manifestations and Complications of Untreated PMD

When Paralysis Metabolic Dysfunction remains unrecognized and untreated, numerous serious complications develop that substantially impact quality of life, functional independence, and longevity in individuals with spinal cord injury. Metabolic derangements accelerate and amplify many secondary complications already associated with SCI, creating a synergistic negative effect on overall health outcomes.

Pressure injuries are a common and serious complication after SCI, and emerging evidence links metabolic abnormalities—particularly metabolic syndrome and diabetes—to higher pressure‑injury risk and delayed wound healing in this population.⁵⁰ The hyperglycemia characteristic of insulin resistance and diabetes impairs microcirculation, reduces collagen synthesis, compromises immune function, and creates a pro‑inflammatory milieu that undermines tissue integrity and repair. Among individuals with SCI, metabolic syndrome and diabetes are associated with substantially higher odds of pressure injury and slower healing, with one study reporting nearly a fourfold increase in pressure ulcer risk in those meeting metabolic syndrome criteria compared with those without.⁵¹

Neurogenic lower urinary tract dysfunction, a common consequence of SCI, becomes substantially more complicated in the setting of diabetes and related metabolic abnormalities. Hyperglycemia promotes urinary tract infections through multiple mechanisms, including glycosuria creating a favorable environment for bacterial growth, impaired neutrophil function compromising immune defense, and microvascular changes affecting bladder tissue perfusion. In individuals with SCI and neurogenic bladder, diabetes and poor glycemic control are associated with higher UTI rates and more frequent recurrent infections compared with those without diabetes, further compounding an already elevated baseline UTI risk.⁵²

Metabolic bone disease represents another area where PMD significantly compounds existing SCI-related pathophysiology. While significant bone mineral density loss occurs in all individuals following SCI, those with metabolic dysfunction experience accelerated bone demineralization and altered bone architecture. The hyperglycemia and hyperinsulinemia characteristic of insulin resistance adversely affect bone remodeling, suppressing osteoblast function and new bone formation while promoting osteoclast activity and bone resorption. Advanced glycation end products accumulate in bone collagen, degrading bone material properties and increasing fragility beyond what is captured by standard bone mineral density measurements. High‑resolution peripheral quantitative CT and related imaging studies in diabetes populations demonstrate substantial deterioration in trabecular and cortical microarchitecture and reduced estimated bone strength at similar areal BMD, helping to explain the higher fracture risk observed in people with diabetes. Extrapolating these mechanisms to SCI, neurogenically driven bone loss combined with diabetes‑related bone quality deficits is expected to further amplify the already elevated risk of fragility fractures in the paralyzed skeleton. ^53,54

Cognitive function, an often overlooked aspect of SCI care, appears to be adversely affected by the combination of spinal cord injury and metabolic dysfunction. Many individuals with SCI show measurable deficits in attention, processing speed, memory, and executive function, and emerging evidence links these impairments to chronic systemic inflammation, neuroinflammation, cerebrovascular pathology, and cardiometabolic risk factors that frequently co‑occur after injury. Systemic inflammatory markers have been shown to partially mediate the association between SCI and cognitive impairment in clinical cohorts, and preclinical models demonstrate that SCI can induce hippocampal mitochondrial abnormalities, reduce dendritic complexity, and produce corresponding cognitive decline. These cognitive effects are thought to be mediated, at least in part, through interacting mechanisms, including cerebral microvascular disease, neuroinflammation, hippocampal mitochondrial dysfunction, and disrupted brain energy metabolism. Spinal cord injury thereby establishes a chronic pro‑inflammatory and metabolically dysregulated milieu that may adversely affect brain structure and function over time, increasing vulnerability to cognitive impairment and highlighting the importance of sustained attention to metabolic health in SCI.^55,56,57

The cumulative effect of these complications translates to significantly reduced life expectancy when PMD remains unaddressed. While improved acute care has substantially increased survival following SCI, those surviving the initial injury and early complications still face a life expectancy that is meaningfully reduced compared with age‑matched able‑bodied individuals, particularly among those with higher‑level and complete injuries or ventilator dependence. Cardiovascular and metabolic conditions—including heart disease, stroke, hypertension, diabetes, and metabolic syndrome—are now among the leading causes of death in people with SCI, and their relative contribution to mortality has increased as sepsis, renal failure, and pneumonia have become better controlled.⁵⁸

Therapeutic Interventions: Functional Electrical Stimulation

Among the various interventions for Paralysis Metabolic Dysfunction, functional electrical stimulation (FES) stands out as a particularly promising approach that directly addresses many of the underlying pathophysiological mechanisms. FES involves the application of low-level electrical currents to activate paralyzed muscles, creating controlled muscle contractions that simulate natural movement patterns. This technology can be deployed in various configurations, including surface electrodes for home-based applications, implanted systems for more precise control, and integrated into modalities such as stationary cycling, rowing, and ambulation systems.⁵⁹ By reactivating paralyzed muscle, FES directly counteracts many of the muscle-specific changes driving metabolic dysfunction, offering a physiologically targeted intervention strategy with substantial evidence supporting its metabolic benefits.⁶⁰

The acute metabolic responses to FES‑mediated exercise include meaningful glucose‑lowering effects, with electrically induced leg exercise shown to blunt post‑prandial hyperglycemia and reduce post‑challenge insulin requirements in individuals with SCI and impaired glucose tolerance. These effects are believed to occur through contraction‑mediated GLUT4 translocation that can bypass impaired insulin signaling, increased blood flow to stimulated muscles that enhances glucose delivery, and activation of AMPK‑related pathways that promote glucose uptake and fatty acid oxidation. Notably, such benefits have been demonstrated in people with chronic SCI who already exhibit marked insulin resistance, underscoring the value of FES‑mediated exercise for those with established metabolic dysfunction. Heart rate and oxygen consumption responses during FES exercise indicate that appropriate protocols can reach moderate‑intensity training domains, providing substantial metabolic stimulus even in the setting of complete paralysis.^{61,62, 63}

Longitudinal studies examining regular electrically induced or FES‑mediated training reveal significant improvements in whole‑body insulin sensitivity, with hyperinsulinemic–euglycemic clamp studies reporting approximately 25% increases in insulin‑stimulated glucose uptake after several months of electrically induced bicycle training in individuals with SCI. Mechanistic investigations indicate that these improvements are accompanied by marked increases in skeletal muscle GLUT4 content and favorable changes in contraction‑ and insulin‑related signaling pathways. Muscle biopsies obtained before and after ES/FES training demonstrate partial reversal of the atrophic, glycolytic muscle phenotype typical of chronic SCI, with increased oxidative enzyme activity and a shift toward more oxidative, fatigue‑resistant fiber characteristics. Together, these structural and metabolic adaptations within paralyzed muscle directly address key components of PMD pathophysiology, providing a targeted intervention for the tissue most affected by paralysis.^64,65

Body composition changes with sustained FES training provide additional metabolic benefits beyond direct effects on glucose metabolism. Studies using computed tomography and magnetic resonance imaging have documented substantial increases in muscle cross‑sectional area after FES training programs, with many cohorts showing double‑digit percentage gains in knee extensor and thigh muscle CSA over 10–24 weeks of regular stimulation. Concurrently, reductions in intramuscular and visceral adipose tissue have been reported following comprehensive ES/FES‑based interventions, sometimes on the order of 10–25% decreases in regional or visceral fat volumes when combined with nutritional strategies. These body composition improvements plausibly contribute to metabolic enhancement through several mechanisms, including increased muscle mass providing greater capacity for glucose disposal, reduced ectopic fat diminishing lipotoxic interference with insulin signaling, and decreased visceral adiposity lowering pro‑inflammatory cytokine production. The net effect can create a virtuous cycle in which improved muscle health and reduced ectopic fat support progressive gains in glucose tolerance and insulin sensitivity.^49,60,66,67

Cardiovascular adaptations to FES training provide significant benefits for individuals with PMD, addressing both metabolic risk factors and cardiovascular deconditioning resulting from paralysis. Regular FES exercise has been shown to improve lipid profiles, with studies documenting increases in HDL-C, reductions in triglycerides, and favorable changes in LDL particle size distribution following 12-16 weeks of training. Vascular adaptations include improved endothelial function, reduced arterial stiffness, and enhanced peripheral blood flow regulation, collectively reducing cardiovascular risk beyond what would be expected from metabolic improvements alone. These cardiovascular benefits are particularly important given the predominance of cardiovascular mortality in chronic SCI populations.⁶⁸

Implementation considerations for FES include careful protocol design tailored to individual circumstances, with parameters including stimulation intensity, frequency, duration, and progression requiring individualization based on injury characteristics, fitness level, and metabolic status. Research indicates that effective metabolic training effects typically require at least three sessions weekly of 30-45 minutes duration, with continued adaptation occurring over 3-6 months of regular training.⁶⁹

Nutritional and Lifestyle Interventions for PMD

Nutritional strategies represent an essential complementary approach to managing Paralysis Metabolic Dysfunction, though they must be specifically tailored to address the unique physiological alterations following spinal cord injury. Energy balance is an important consideration due to the significantly reduced energy requirements following SCI. Indirect calorimetry studies in individuals with spinal cord injuries have documented lower resting metabolic rates than predicted by standard equations for able-bodied individuals, with complete injuries and higher levels of injury associated with greater reductions. Careful attention to energy balance represents an essential but often overlooked component of metabolic management following SCI.^70,71,72

Macronutrient composition of the diet significantly influences glucose metabolism and insulin sensitivity following SCI, and lower‑carbohydrate patterns that emphasize higher protein and healthy fats appear particularly promising for managing PMD. Randomized trials of low‑carbohydrate, high‑protein diets with healthy fat sources in adults with chronic SCI and insulin resistance have demonstrated favorable changes in body composition and blood lipid profiles, including reductions in total and visceral fat mass.⁷³

In parallel, lifestyle interventions that combine structured dietary modification with increased physical activity have produced significant improvements in fasting glucose and insulin, oral glucose tolerance, and broader cardiometabolic risk markers in this population. These benefits are thought to arise from lowering dietary glycemic load and added sugars, thereby reducing chronic hyperinsulinemia, limiting hepatic de novo lipogenesis—the process by which the liver converts excess carbohydrate into new fat—and reducing ectopic fat–related interference with insulin signaling in liver and skeletal muscle, where accumulated fat can disrupt how cells respond to insulin.⁷⁴

Importantly, in addition to lower carbohydrate, carbohydrate quality considerations are equally relevant, with evidence supporting emphasis on low glycemic index carbohydrates rich in fiber to attenuate postprandial glucose excursions and support favorable gut microbiome composition. These approaches align with mounting evidence in the broader diabetes prevention literature while addressing the specific metabolic vulnerabilities associated with paralysis.⁷⁵

Protein requirements warrant special consideration in SCI, balancing the need to preserve lean mass against concerns regarding kidney function in a population with elevated risk for urological complications. Research indicates that moderately increased protein intake supports preservation of lean mass and enhances metabolic health in SCI populations, particularly when combined with appropriate physical activity interventions such as FES. The anabolic resistance characteristic of paralyzed muscle may necessitate strategic protein distribution throughout the day to maximize muscle protein synthesis, with evidence supporting 20-30g of high-quality protein per meal including sufficient leucine to overcome this resistance. Particular attention to adequate protein intake during periods of increased catabolic stress, such as during pressure injury healing or intercurrent illness, remains essential to prevent accelerated muscle loss that would further compromise metabolic health.⁷⁶

In parallel, lifestyle interventions that combine structured dietary modification with increased physical activity have produced significant improvements in fasting glucose and insulin, oral glucose tolerance, and broader cardiometabolic risk markers in people with SCI. In a year‑long adaptation of the Diabetes Prevention Program for individuals with chronic SCI, a therapeutic lifestyle intervention that integrated a calorie‑restricted Mediterranean‑style diet, circuit resistance training three times per week, and structured behavioral support led to clinically meaningful reductions in body mass and total fat mass, lower fasting and 2‑hour OGTT glucose and insulin levels, improved insulin sensitivity indices and HbA1c, and more favorable lipid profiles, including decreases in total cholesterol, triglycerides, and LDL‑cholesterol with an increase in HDL‑cholesterol. These benefits illustrate the potential of coordinated diet‑plus‑exercise programs to address the clustered cardiometabolic abnormalities characteristic of PMD after SCI.⁷⁷

Micronutrient considerations in SCI require attention to several nutrients with particular relevance to metabolic health. Vitamin D deficiency occurs with concerning frequency in SCI populations due to reduced sun exposure, decreased outdoor activity, possible medication interactions, and altered metabolism, with studies reporting suboptimal 25(OH)D levels in approximately two‑thirds to more than 90% of individuals with chronic SCI. This deficiency has important implications beyond bone health, as vitamin D is involved in regulation of insulin secretion and insulin sensitivity and modulates inflammatory and immune pathways that contribute to cardiometabolic risk.⁷⁸

Implementation of nutritional interventions for PMD requires consideration of practical challenges unique to the SCI population, including autonomic dysfunction affecting gut motility, altered satiety signaling, medication interactions, and potential physical limitations impacting food preparation. Adaptive approaches that accommodate these challenges while progressively implementing metabolic-focused nutritional strategies show greatest success. Integration of nutrition interventions with other management approaches, particularly physical activity through FES or other accessible modalities, demonstrates synergistic benefits exceeding those achieved with either intervention alone.

Final Reflection

Paralysis Metabolic Dysfunction represents a distinct and clinically significant syndrome encompassing the constellation of metabolic alterations that develop following spinal cord injury. The progressive nature of these changes---beginning with immediate post-injury catabolism and evolving through chronic adaptations in muscle physiology, adipose tissue distribution, and systemic inflammation---creates a perfect storm for insulin resistance, dyslipidemia, and ultimately increased cardiovascular risk. The recognition of PMD as a defined clinical entity emphasizes the critical importance of metabolic health in determining long-term outcomes following SCI and highlights opportunities for targeted intervention that could substantially impact quality and quantity of life for this population. The evidence reviewed in this article demonstrates that PMD is not merely an inevitable consequence of paralysis but rather a modifiable condition amenable to various intervention strategies.

Functional electrical stimulation emerges from this review as a particularly promising intervention directly addressing core aspects of PMD pathophysiology. By reactivating paralyzed muscle, FES counteracts the fiber-type shifting, atrophy, and metabolic alterations that significantly contribute to insulin resistance and dyslipidemia. The documented improvements in glucose tolerance, insulin sensitivity, body composition, and cardiovascular health following FES interventions provide compelling evidence for its incorporation into standard care approaches for metabolic health in SCI.

Nutritional strategies tailored to the unique physiological alterations following SCI provide important complementary approaches, with evidence supporting energy balance management, strategic macronutrient composition, and attention to meal timing and micronutrient status. Together with appropriate pharmacological management when indicated, these interventions offer a comprehensive approach to addressing the multifaceted pathophysiology of PMD.

The implementation of routine metabolic screening, early intervention, and ongoing management of PMD would represent a significant advance in SCI care, potentially modifying the current trajectory toward early cardiometabolic morbidity and mortality that characterizes many cases of chronic SCI. This approach aligns with the broader evolution of SCI care from a primarily impairment-focused model toward a comprehensive wellness approach addressing the multiple secondary health conditions that significantly impact quality of life and longevity. Healthcare systems, providers, researchers, and individuals with SCI all have important roles in advancing awareness, understanding, and management of this important aspect of post-SCI health. Through continued research, clinical innovation, and systematic implementation of evidence-based approaches, we can substantially improve metabolic health outcomes for the SCI population and reduce the significant burden associated with the metabolic and physiological alterations that occur after spinal cord injury.

GlenHouse, MD

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52. Du H, Li Z, Zhang J, Wang X, Jing Y, Yang D, Li J. Traumatic spinal cord injury: identifying independent risk factors and predictive model development for symptomatic urinary tract infections. PeerJ. 2025 May 28;13:e19473. doi: 10.7717/peerj.19473.

53. Jiang SD, Jiang LS, Dai LY. Mechanisms of osteoporosis in spinal cord injury. Clin Endocrinol (Oxf). 2006 Nov;65(5):555-65. doi: 10.1111/j.1365-2265.2006.02683.x.

54. McMillan DW, Nash MS, Gater DR Jr, Valderrábano RJ. Neurogenic Obesity and Skeletal Pathology in Spinal Cord Injury. Top Spinal Cord Inj Rehabil. 2021;27(1):57-67. doi: 10.46292/sci20-00035.

55. Hu X, Wu L, Wen Y, Liu J, Li H, Zhang Y, Wang Z, Ding J, Zeng Z, Xia H. Hippocampal Mitochondrial Abnormalities Induced the Dendritic Complexity Reduction and Cognitive Decline in a Rat Model of Spinal Cord Injury. Oxid Med Cell Longev. 2022 May 4;2022:9253916. doi: 10.1155/2022/9253916.

56. Zhang WQ, Wu JP, Yu L, Zhang CH, Zhang HL, Guo P, Feng YG, Cui ZW. Association Between Spinal Cord Injury and Cognitive Impairment, and the Mediating Role of Inflammation. J Craniofac Surg. 2025 Sep 1;36(6):e799-e803. doi: 10.1097/SCS.0000000000011593. Epub 2025 Jun 26.

57. Alcántar-Garibay OV, Incontri-Abraham D, Ibarra A. Spinal cord injury-induced cognitive impairment: a narrative review. Neural Regen Res. 2022 Dec;17(12):2649-2654. doi: 10.4103/1673-5374.339475.

58. Cragg JJ, Noonan VK, Krassioukov A, Borisoff J. Cardiovascular disease and spinal cord injury: results from a national population health survey. Neurology. 2013 Aug 20;81(8):723-8. doi: 10.1212/WNL.0b013e3182a1aa68. Epub 2013 Jul 24.

59. Martin R, Sadowsky C, Obst K, Meyer B, McDonald J. Functional electrical stimulation in spinal cord injury:: from theory to practice. Top Spinal Cord Inj Rehabil. 2012 Winter;18(1):28-33. doi: 10.1310/sci1801-28.

60. Griffin L, Decker MJ, Hwang JY, Wang B, Kitchen K, Ding Z, Ivy JL. Functional electrical stimulation cycling improves body composition, metabolic and neural factors in persons with spinal cord injury. J Electromyogr Kinesiol. 2009 Aug;19(4):614-22. doi: 10.1016/j.jelekin.2008.03.002. Epub 2008 Apr 25.

61. Dolbow DR, Davis GM, Welsch M, Gorgey AS. Benefits and interval training in individuals with spinal cord injury: A thematic review. J Spinal Cord Med. 2022 May;45(3):327-338. doi: 10.1080/10790268.2021.2002020. Epub 2021 Dec 2.

62. Jeon, J., Weiss, C., Steadward, R. et al. Improved glucose tolerance and insulin sensitivity after electrical stimulation-assisted cycling in people with spinal cord injury. Spinal Cord 40, 110–117 (2002). doi.org/10.1038/sj.sc.3101260

63. Petrie MA, Kimball AL, Shields RK. Acute Low Force Electrically Induced Exercise Modulates Post Prandial Glycemic Markers in People with Spinal Cord Injury. J Funct Morphol Kinesiol. 2022 Oct 17;7(4):89. doi: 10.3390/jfmk7040089.

64. Jeppesen, T. D., Dela, F., Vissing, J., & Beck-Nielsen, H. Insulin action and long-term electrically induced training in individuals with spinal cord injuries. Spinal Cord. 2001;39(9):514–519.

65. Hooker, S. P., Figoni, S. F., Glaser, R. M., Rodgers, M. M., Mathews, T., Suryaprasad, A. G., et al. Improved glucose tolerance and insulin sensitivity after electrical stimulation‑assisted cycling in people with spinal cord injury. Spinal Cord. 2002;40(3):110–117.

66. Effects of Electrical Stimulation Training on Body Composition Parameters After Spinal Cord Injury: A Systematic Review. Bekhet, Amira Hassan et al. Archives of Physical Medicine and Rehabilitation, Volume 103, Issue 6, 1168 - 1178

67. 49.Gorgey AS, Wells KM, Austin TL. Adiposity and spinal cord injury. World J Orthop. 2015 Sep 18;6(8):567-76. doi: 10.5312/wjo.v6.i8.567.

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69. van der Scheer JW, Goosey-Tolfrey VL, Valentino SE, Davis GM, Ho CH. Functional electrical stimulation cycling exercise after spinal cord injury: a systematic review of health and fitness-related outcomes. J Neuroeng Rehabil. 2021 Jun 12;18(1):99. doi: 10.1186/s12984-021-00882-8.

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71. Gorgey AS, Khalil RE. Positive and negative energy surpluses in persons with chronic spinal cord injury. Br J Nutr. 2025 Dec 26:1-11. doi: 10.1017/S0007114525105953.

72. Farkas GJ, Gorgey AS, Dolbow DR, Berg AS, Gater DR. Caloric Intake Relative to Total Daily Energy Expenditure Using a Spinal Cord Injury-Specific Correction Factor: An Analysis by Level of Injury. Am J Phys Med Rehabil. 2019 Nov;98(11):947-952. doi: 10.1097/PHM.0000000000001166.

73. Li J, Gower B, McLain A, Yarar-Fisher C. Effects of a low-carbohydrate/high-protein diet on metabolic health in individuals with chronic spinal cord injury: An exploratory analysis of results from a randomized controlled trial. Physiol Rep. 2022 Nov;10(22):e15501. doi: 10.14814/phy2.15501.

74. Bigford GE, Lehmann DA, Betancourt LF, Maher JL, Mendez AJ, Nash MS. Modification of the Diabetes Prevention Program Lifestyle Intervention in Persons with Spinal Cord Injury: Efficacy for Reducing Major Cardiometabolic Risks, Increased Fitness, and Improved Health-Related Quality of Life. J Spine Res Surg. 2024;6(1):10.26502/fjsrs0070. doi: 10.26502/fjsrs0070.

75. Ni Y, Zheng A, Hu Y, et al. Compound dietary fiber and high-grade protein diet improves glycemic control and ameliorates diabetes and its comorbidities through remodeling the gut microbiota in mice. Front Nutr. 2022;9:959703. doi:10.3389/fnut.2022.959703.

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78. Flueck, J., Perret, C. Vitamin D deficiency in individuals with a spinal cord injury: a literature review. Spinal Cord 55, 428–434 (2017). https://doi.org/10.1038/sc.2016.155

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Inspired by: Gater DR Jr, Farkas GJ, Tiozzo E. Pathophysiology of neurogenic obesity after spinal cord injury. Topics in Spinal Cord Injury Rehabilitation. 2021;27(1):1–10.

When people talk about “losing fat,” they usually mean the soft layer under the skin. But after a spinal cord injury (SCI), where fat is stored in the body is even more important than how much there is.

Two main types of fat matter most here: subcutaneous fat (under the skin) and visceral fat (around the organs).

Two Kinds of Fat: One You Can Pinch, One You Can’t

1. Subcutaneous Adipose Fat (SAT)

2. Visceral Adipose Fat (VAT)

Subcutaneous fat: the pinchable kind

Subcutaneous adipose tissue (often shortened to SAT) is the fat that sits just beneath the skin, in areas like the buttocks, thighs, back, and the front and sides of the abdomen. It is what most people feel when they “pinch an inch.”

Subcutaneous adipose tissue (SAT) stores energy, cushions the body, and is less inflammatory than visceral fat, so it is generally a safer place to park extra calories.

When it can expand, especially in the hips and thighs, SAT acts like a “metabolic sink,” safely holding fat that might otherwise spill into the liver, pancreas, and muscles and drive diabetes and abnormal cholesterol.

The downside is that as subcutaneous fat cells become full and then become insulin resistance, they then start to leak free fatty acids and inflammatory signals (called cytokines), so SAT is helpful rather than harmless—but still a lot better than visceral fat around the organs.

Visceral fat: the hidden troublemaker

Visceral adipose tissue (VAT) is deeper fat located inside the abdomen, mainly in the mesentery and greater omentum (pictured above)— tissues that anchor and cover your intestines and other organs. You cannot grab it with your hands or see it directly in the mirror.

• VAT tends to have larger fat cells, and is strongly associated with high free fatty acids, high total and LDL cholesterol, high triglycerides, and low HDL (“good”) cholesterol.

• This is the common pattern seen in most spinal cord injured patients

• This pattern contributes to systemic inflammation, insulin resistance, and atherosclerosis, and increases the risk for type 2 diabetes and cardiovascular disease.

Because VAT also accumulates around the kidneys, it can contribute to high blood pressure by physically compressing the kidneys and promoting hormonal changes that raise blood pressure.

Why VAT Is Metabolically Different

Even if two people have the same body weight, the one with more visceral fat usually has a higher risk of metabolic syndrome.

Visceral fat behaves differently because:

• It releases more inflammatory signals. The paper describes visceral and other white fat depots producing inflammatory cytokines (TNFα, IL-1β, IL-6, MCP-1, NFκB) that drive systemic, low-grade inflammation and interfere with insulin signaling. This can lead to insulin resistance and metabolic problems.

• It drives abnormal blood fats. Larger visceral adipocytes (fat cells) release more nonesterified free fatty acids (NEFAs), feeding the liver with excess fat, which leads to higher triglycerides, higher LDL, higher apoB, and lower HDL. This pattern is undesirable and consistent with metabolic dysfunction. For better health you want lower triglycerides, lower LDL, and higher HDL.

• It promotes insulin resistance. NEFAs and inflammatory molecules activate intracellular pathways that block the insulin signaling cascade needed for glucose uptake, leading to hyperglycemia (high glucose) and hyperinsulinemia (high insulin) and, eventually, type 2 diabetes.

How This Plays Out After Spinal Cord Injury

The article emphasizes that individuals with SCI have a unique physiology: sarcopenia (muscle loss), neurogenic osteoporosis, anabolic hormone deficiency, sympathetic dysfunction, and blunted satiety. All of this reshapes energy balance and body composition.

Key points:

• Lower energy out, higher energy in. Resting metabolic rate and physical activity–related energy expenditure fall because of loss of metabolically active muscle and bone, decreased sympathetic nervous system activity, and hormonal changes. At the same time, satiety (the feeling of fullness) signals may be blunted, and energy intake often exceeds measured energy expenditure.

• Neurogenic obesity and body composition. Because of this mismatch, many people with SCI develop what the authors call “neurogenic obesity”: excess fat mass (often with more VAT) combined with muscle and bone loss.

• Obesity is common, but BMI (Body Mass Index) underestimates it. Multiple studies cited in the paper show obesity rates of 67–97% in SCI when defined by body fat percentage or adapted BMI cutoffs (BMI ≥22 kg/m² or body fat >22% for men and >35% for women).

I am not a fan of BMI or waist circumference in spinal cord injury. Future newsletter to discuss this in detail.

This combination of high fat, low muscle, and altered autonomic and hormonal regulation creates a “perfect storm” for Paralysis Metabolic Dysfunction in SCI.

Why This Matters for Everyday Health

For people living with SCI, neurogenic obesity is not just about appearance; it is tied to real, measurable health risks.

The article links neurogenic obesity to:

• Systemic inflammation: Driven by adipose-derived cytokines and macrophage activation in white adipose tissue.

• Hyperglycemia and diabetes: Obesity-related insulin resistance, NEFA overload, and inflammatory signaling all contribute to glucose intolerance and type 2 diabetes in SCI.

• Dyslipidemia: Elevated triglycerides, increased VLDL and LDL, reduced HDL, and dysfunctional HDL particles, all increasing the risk of atherosclerosis.

• Hypertension: Initially, many people with higher-level SCI experience low blood pressure due to sympathetic blunting, but as adiposity (especially VAT) increases, mechanisms like leptin resistance, sympathetic nervous system activation, and kidney compression can lead to high blood pressure.

Because of this, the authors and related guidelines recommend more aggressive and earlier screening for metabolic syndrome and cardiometabolic disease in SCI and using SCI-specific definitions of obesity.

Screening labs that I order at least annually, but preferably twice a year, especially if trying to:

• Monitor a lab that is outside of the desirable range

• Changes are being made and results need to be followed

• Making sure to get on top of abnormalities when there’s a hint, you’re heading towards an abnormal number—e.g., increasing fasting glucose or rising A1c.

The Labs:

• CBC (complete blood count)

• CMP (comprehensive metabolic panel) and Cystatin-C to better evaluate renal function in SCI

• Lipid panel (NMR)

• HbA1c

• ApoB

• Homocysteine

• hs-CRP

• Vitamin D (25-OH)

• Fasting insulin

• Oral Glucose Tolerance Test (OGTT): baseline, one hour, and two hours - ideally with a continuous glucose monitor (CGM)

  Glen House, MD

(More below…)

Deeper Dive (for Inquisitive Readers)

The paper by Gater and colleagues frames neurogenic obesity as a distinct clinical entity that extends beyond sarcopenic obesity by incorporating neurogenic osteoporosis, anabolic deficiency, sympathetic dysfunction, and blunted satiety, all driven by SCI-associated neural and hormonal changes. Total daily energy expenditure (TDEE) falls due to loss of metabolically active fat-free mass (muscle and bone), reduced anabolic hormones (e.g., testosterone, growth hormone/IGF-1), and diminished sympathetic drive, while vagal sensory changes and altered satiety lead to energy intake that often exceeds measured needs.

In upcoming newsletters, I’ll take a closer look at energy expenditure in individuals with spinal cord injury, exploring how it varies across different injury levels and why meeting standard exercise recommendations is often physiologically unattainable. I’ll also discuss why diet and nutrition must serve as the cornerstone of health and wellness in this population.

White adipose tissue in this context becomes pathologic. As adipocytes hypertrophy and the depot expands, the stromal compartment accumulates M1 macrophages that secrete TNFα, IL-1β, IL-6, MCP-1, and activate NFκB, leading to systemic low-grade inflammation. VAT is characterized by larger adipocytes and is closely linked with dyslipidemia, including increased NEFAs, total cholesterol, LDL-C, ApoB, and triglycerides, and reduced HDL-C, whereas SAT is more closely tied to insulin resistance. Excess NEFAs and their metabolites (acyl-CoA, ceramides, diacylglycerol) activate PKC, JNK, and IKKβ, which impair IRS-1/IRS-2 phosphorylation and disrupt the PI3K/AKT pathway, blocking GLUT4 translocation and causing insulin resistance in liver, muscle, and adipose tissue. This is specifically related to the “insulin-dependent” pathway.

The dyslipidemic profile arises as insulin’s normal suppressive effects on lipolysis, apoB production, and VLDL secretion are lost, leading to hypertriglyceridemia, increased VLDL-C and LDL-C, reduced apoA production, and dysfunctional HDL.

This leads to the classic metabolic pattern often seen in individuals with spinal cord injury—marked by elevated triglycerides and significantly reduced HDL cholesterol—a profile consistent with accelerated atherosclerosis.

Hypertension in this setting reflects multiple obesity-related mechanisms: leptin resistance and leptin-driven aldosterone synthase activation, heightened muscular and renal sympathetic activity, RAAS activation with angiotensin II–mediated vasoconstriction and further impairment of vascular insulin signaling, and mechanical renal compression from perirenal and retroperitoneal fat that can raise blood pressure by 35–40 mm Hg.

This rise in blood pressure tends to occur later in the course of spinal cord injury, contrasting with the relative hypotension typically observed during the first several years—or even decades—after injury.

Metabolic syndrome prevalence in SCI exceeds 50% in several cohorts, but estimates vary depending on which diagnostic criteria (WHO, NCEP ATP III, IDF, NHLBI/AHA) are applied, partly because there is no universally accepted SCI-specific screening tool for obesity and metabolic syndrome. The authors argue that physiological changes in adipose tissue after SCI should be labeled as neurogenic obesity and that clinicians should adopt lower BMI thresholds and body fat–based definitions, while prioritizing research and clinical programs focused on SCI-tailored exercise and nutrition interventions to prevent and manage this high-risk metabolic phenotype.

I agree with the authors in recognizing and adopting the term “neurogenic obesity.” It is a real and clinically meaningful condition with significant consequences if left unaddressed. I specifically focus on neurogenic obesity, as I believe it represents an upstream driver that can be mitigated to substantially improve metabolic dysfunction.

Glen House, MD

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Insulin is one of the body’s master traffic controllers. It decides where sugar goes, whether we burn it, and whether we store it as fat. When insulin’s message stops getting through—a state called insulin resistance—blood sugar climbs, fat storage ramps up, and the risk of diabetes and heart disease rises.

What Insulin Actually Does

Think of insulin as a “messenger” your pancreas sends out after you eat.

• When you eat and blood sugar rises, your pancreas releases insulin into the bloodstream.

• Insulin circulates and “knocks” on cells in muscle, fat, and liver, asking them to pull sugar out of the blood and bring it inside.

• Once sugar is inside, cells can burn it for energy or store it for later as glycogen or fat.

If insulin does its job well, blood sugar stays in a healthy, steady range: not too high, not too low.

Locks, Keys, and Little Doors

The image above shows a muscle cell membrane with green “doors” called GLUT4. Here’s the plain‑English version of what’s going on.

- Insulin is like a “key” circulating in your blood.

- Muscle cells have insulin receptors on their surface—think of these as locks or doorbells.

- When insulin binds its receptor (key in lock), it triggers a chain reaction inside the cell (the insulin‑dependent pathway in the picture).

- That chain reaction tells storage vesicles full of GLUT4 “doors” to move up to the cell surface and plug in.

- More GLUT4 at the surface means more doors for sugar to walk through, so more glucose leaves the bloodstream and enters the muscle.

Inside the cell, there’s a whole network of tiny biochemical “steps” that carry the message along from insulin’s knock on the outside to those GLUT4 doors sliding open on the surface. In plain language, insulin is just telling the cell, “Open more doors for sugar.”

Muscle Contraction: A Different Pathway

The right side of the image shows a runner (emphasizing a muscle contraction mechanism) and the “insulin‑independent” pathway.

Here’s the key idea:

- When someone contract their muscles (walking, FES, or even spasticity), the muscle itself sends signals—through molecules like AMPK, calcium (Ca), and reactive oxygen species (ROS) and nitrogen species (NO)—that also move GLUT4 doors to the surface.

- In other words, exercise can open sugar doors even without insulin. It’s a separate route that triggers the same GLUT4 doors.

If insulin is the key, muscle contraction is like a manual override that can still open the doors when the lock is getting rusty.

What Is Insulin Resistance?

Insulin resistance is what happens when those same cells stop listening well to insulin’s message.

- The pancreas is still making insulin (often even more than before), but the muscle, fat, and liver cells don’t respond as strongly. It now takes more insulin to open the same number of sugar doors.

- As a result, sugar lingers in the bloodstream instead of moving efficiently into cells.

- Over time, the pancreas can get worn out from constantly working in overdrive, and blood sugar begins to rise into the prediabetes and then type 2 diabetes range.

A lay analogy: insulin is “shouting,” but the cells have turned the volume down. The message eventually gets through, but only if the pancreas yells louder and louder.

The analogy I often use is that the pancreas keeps pumping out more and more insulin just to hold blood sugar at the same level. It’s like driving 50 miles an hour in first gear: you can do it for a while, but eventually you burn out the engine—and the same thing can happen to your pancreas.

Why Insulin Resistance Matters So Much

Insulin resistance does not just affect blood sugar; it reshapes metabolism.

- Chronically elevated insulin and blood sugar are linked to type 2 diabetes, fatty liver disease, high triglycerides, and an increased risk of heart disease.

- Fat storage becomes easier, fat burning becomes harder, and energy levels can fluctuate because fuel is in the wrong place—stuck in the bloodstream or in fat cells instead of in muscles.

The point of understanding insulin signaling is not to memorize pathways, but to recognize that everyday choices—what and when we eat, how much we move, how we sleep and manage stress—change how well our cells “hear” insulin.

Where We’re Going Next

In upcoming newsletters, we’ll explore practical levers you can pull to improve insulin sensitivity:

- Food patterns that keep insulin spikes in check

- Various ways to prevent the car from driving 50 miles an hour first gear and burning out the pancreas

- The roles of sleep, stress, and body composition

For now, the big takeaway is simple: insulin is your body’s sugar traffic controller, GLUT4 are the doors it opens, and insulin resistance is what happens when those doors stop responding. Understanding that picture makes the rest of metabolic health much easier to follow.

Do not fret: upcoming newsletters will walk through practical ways to lower blood glucose, smooth out rapid spikes, and improve insulin resistance. Improving metabolic health after spinal cord injury.

Glen House, MD

Hello, and thank you for visiting my Substack!

My name is Glen House, MD, and I’m excited to share this platform with you as we explore the unique metabolic and systemic changes caused by spinal cord injury/disorder (SCI/D). Living with paralysis introduces distinct challenges that differ from those seen in the general population, particularly when it comes to metabolic health. These changes are what I call Paralysis Metabolic Dysfunction, a concept I’ll be diving into in much greater detail throughout this newsletter series.

This Substack will focus primarily on metabolic health as the cornerstone of longevity after SCI. However, I’ll also cover broader topics that influence long-term health and when able, provide actionable steps to help you achieve your goals. My mission is to bring the detailed science and research behind these changes to the public, empowering you with knowledge to better understand your metabolic health and guide your approach to living well after spinal cord injury. In addition, I will explore lifestyle opportunities that potentially enhance a lived experience.

My Journey

At age 20, during my college years, my life changed forever when I sustained a spinal cord injury snow skiing. This experience shaped not only my personal journey but also my professional path. I became board-certified in Physical Medicine & Rehabilitation with sub-specializations in spinal cord medicine and brain injury medicine. Over the past 15 years, I’ve focused intensely on understanding how SCI impacts metabolic health—not just for myself but for others navigating similar challenges.

In 2022, I was invited to speak at the Metabolic Health Summit, where I shared my insights into SCI-related metabolic dysfunction. Preparing for this lecture was transformative—it allowed me to synthesize years of research into a framework that captures the unique metabolic consequences of paralysis. This framework is built around three key components that form the basis of Paralysis Metabolic Dysfunction:

The Paralysis Metabolic Dysfunction Triad

1. Visceral Adipose Tissue Accumulation
   Paralysis leads to profound changes in body composition, including increased visceral fat deposition. Unlike subcutaneous fat, visceral fat is metabolically active and contributes significantly to chronic inflammation, insulin resistance, and cardiovascular risk. This accumulation occurs rapidly after SCI and magnifies the metabolic syndrome seen in the general population.

2. Metabolic Cellular Changes
   At the cellular level, SCI disrupts mitochondrial function, glucose metabolism, and lipid processing. These changes impair energy production and lead to systemic dysfunction. For example, skeletal muscle below the injury level undergoes metabolic reprogramming, reducing its ability to regulate glucose uptake effectively. Future newsletters will delve into the detailed science behind these cellular changes and their implications for overall health.

3. Muscle Changes
   Paralysis results in a loss of voluntary muscle activation below the injury level, leading to muscle atrophy, intramuscular fat accumulation, and diminished metabolic activity. Muscle contraction plays a critical role in glucose regulation; without it, insulin resistance develops rapidly. This mechanical disruption is foundational to many downstream effects of Paralysis Metabolic Dysfunction.

These three components are interconnected yet distinct from general metabolic syndrome. They amplify its effects while presenting unique challenges specific to those living with SCI. My goal is to explain the science behind these changes in future newsletters so you can fully understand your metabolic health and take informed steps toward improvement.

Nutritional Strategies: The Bedrock of Metabolic Health

Over the past decade and a half, I’ve focused extensively on nutritional interventions as the foundation for addressing Paralysis Metabolic Dysfunction—and for good reason. Without proper nutrition tailored to mitigate inflammation, regulate glucose levels, and optimize energy balance, all other interventions become far less effective.

Nutritional strategies should be viewed as the bedrock upon which other approaches like exercise or emerging therapies are built. For individuals with SCI, nutrition plays a pivotal role in managing visceral adipose tissue accumulation while supporting cellular function and overall longevity. Some key principles include:

• Reducing Inflammation

• Optimizing Macronutrient Balance

• Supporting Mitochondrial Health

• Maintaining Caloric Control

The results I’ve seen—both personally and professionally—underscore how transformative nutritional interventions can be when applied consistently over time. Future newsletters will provide actionable guidance on crafting an effective nutrition plan tailored specifically for individuals with SCI.

Why This Matters

Spinal cord injury presents unique challenges that require tailored solutions—not just ensuring health but thriving. By addressing Paralysis Metabolic Dysfunction through nutritional strategies and other interventions like exercise or emerging therapies, it is possible to empower individuals with SCI to take proactive steps toward better health outcomes.

Join Me on This Journey

Through this Substack, I’ll share information designed to help you improve your metabolic health and longevity after spinal cord injury. This will include studies I will highlight, information I have gathered over the years, and my personal experiences as it relates to my own Paralysis Metabolic Dysfunction. I will openly share my approaches and results. Please note that this content is not medical advice; any interventions should be discussed with your healthcare provider before implementation.

While the core of this Substack centers on metabolic health after spinal cord injury, my mission extends to any topic that can improve health, longevity, and quality of life for people living with spinal cord impairments. Whether you’re navigating these challenges yourself or supporting someone who is, you’ll find evidence-based insights and actionable guidance here to help you live better and longer after spinal cord injury.

Thank you for joining me—I’m excited to share what I’ve learned and continue exploring new possibilities together for a long and healthy life with SCI. There's a lot of good news to share!

Glen House, MD