Insulin Resistance Isn’t Caused by Carbs (or Sugar) — It’s Caused by a Broken Metabolism
Why cutting carbs doesn’t fix the root cause—and why sugar is part of the solution
Obesity, type 2 diabetes, heart disease, and even Alzheimer’s are all part of what we call Metabolic Syndrome—a cluster of conditions tied together by one central dysfunction: insulin resistance.
Most doctors and even some nutritionists still cling to the idea that carbs (especially sugar) cause insulin resistance and that the fix is cutting sugar out of the diet. But that framework is outdated, oversimplified, and—let’s be honest—causing more harm than good.
From a pro-metabolic perspective, insulin resistance doesn’t come from eating too many carbs. It comes from the body’s inability to use them properly. That’s a huge difference—and it completely changes the solution.
🍭 Sugar Is Not the Enemy. It’s Actually a Healing Food.
Let’s get this straight up front: Sugar is not inherently bad for you. In fact, sugar—especially the kind that comes from ripe fruit, honey, dairy, and even plain white sugar—can be one of the most metabolically supportive fuels on the planet.
According to Dr. Ray Peat and other scientific researchers like Kaya at Fundamental Nourishment, sugar is:
The preferred fuel of the liver, brain, and thyroid
Required for glycogen storage in the liver and muscles
A potent cortisol-lowering agent when eaten correctly
Necessary for the conversion of inactive thyroid hormone (T4) to active thyroid hormone (T3)
In other words, your body is hardwired to run on sugar. It doesn’t cause insulin resistance—it prevents it by keeping stress hormones low, thyroid function high, and energy production efficient.
So why do people blame sugar?
Because most people are consuming it in the context of a broken metabolism—one suppressed by under-eating, chronic stress, polyunsaturated fats (PUFAs), and a diet too low in the nutrients needed to actually process carbohydrates (like magnesium, potassium, and B vitamins). It’s the context, not the carbohydrate.
🤯 What Really Causes Insulin Resistance?
Insulin resistance is not caused by “eating too many carbs.” It’s caused by metabolic stress—when your cells can’t use glucose efficiently due to mitochondrial dysfunction, nutrient deficiencies, and stress hormone dominance.
Here’s what’s really driving it:
PUFA buildup in tissues
Cortisol and adrenaline dominance
Low thyroid function
Nutrient deficiencies (magnesium, potassium, vitamin B1, B3)
Undereating (especially carbs)
Mitochondrial downregulation from chronic stress
When cells are stressed, they can’t burn glucose well. So insulin rises to try to push that glucose in. Over time, cells stop responding. The solution isn’t to cut out the glucose—it’s to restore the cell’s ability to use it.
💡 Muscle Is the Key to Burning Sugar (and Fat)
The first tissue to become insulin resistant is usually skeletal muscle. That matters, because muscle is where most of your glucose is burned. If muscle cells aren’t responding to insulin, glucose gets shunted to fat cells instead. You gain weight—not because you’re eating sugar, but because your body can’t burn sugar well.
And ironically, the more you cut carbs, the worse this gets. Low-carb, high-fat diets reduce thyroid output, increase cortisol, and flood your tissues with fatty acids that interfere with glucose metabolism (this is the Randle Cycle in action).
That’s why people often gain weight when they “fall off” keto—it’s not a lack of willpower. It’s a metabolism that was running on fumes.
🔥 How to Actually Restore Insulin Sensitivity
The good news? Insulin resistance is reversible when you fix what caused it in the first place: a stressed, underfueled metabolism. The solution isn’t fear—it’s fuel. Sugar isn’t the villain. It’s part of the repair kit.
First and foremost, you need to eat enough. Chronic undereating—especially low-carb dieting—suppresses your thyroid, depletes glycogen, and keeps cortisol elevated. That combo destroys your metabolic flexibility. Most women healing their metabolism need at least 2000–2500 calories per day, with 50–60% of those calories coming from carbs. And not just any carbs—easy-to-digest, pro-metabolic carbs like fruit, juice, honey, dairy sugars, white sugar, and root vegetables.
Equally important is keeping fat intake low, especially during the healing phase. This isn’t about fearing fat forever—but excess fat, especially from seed oils and PUFAs, inhibits your ability to burn glucose. That’s why we cap fat at around 10–15% of total calories for those reversing insulin resistance. Stick to saturated fats from coconut oil, cacao, dairy, or a little butter—but keep portions modest while your body is relearning how to burn sugar.
Next, focus on supporting muscle tissue. Muscle is your best friend in this process because it is where most of your glucose disposal happens. The more muscle you have, the more carbs you can handle. But even more important than size is glucose uptake capacity. Resistance training a couple of times per week, paired with walking 8–10k steps per day, is often enough to massively improve insulin sensitivity—without wrecking your adrenals.
🧠 Metabolic Healing Is a Whole-Body Job
Beyond food and movement, don’t overlook your environment. Sunlight helps regulate your circadian rhythm, stimulates dopamine and vitamin D production, and supports healthy thyroid and adrenal output. Prioritize at least 30 minutes of outdoor light daily—bonus points if it’s in the morning.
Sleep is non-negotiable. Most of your cellular repair, hormone conversion, and liver detoxification happens at night. If you’re wired and tired, consider a bedtime snack that combines sugar + protein—like warm milk with honey or cottage cheese with jam—to stabilize blood sugar and lower cortisol overnight.
Finally, make sure you’re getting the key nutrients your metabolism needs to process carbohydrates: magnesium, potassium, sodium, thiamine (B1), and niacinamide (B3). You can get most of these from food, but strategic supplementation can be helpful in more depleted or chronically stressed individuals.
🚨 What About Fructose and Fatty Liver?
Fructose gets a bad rap—usually from people who conflate fruit with soda. But context is everything. When fructose is consumed in a low-fat, nutrient-dense environment (think fruit + protein, or honey + dairy), it is quickly burned or stored as liver glycogen—fuel for your thyroid, brain, and adrenals.
The real issue is when refined fructose is consumed alongside seed oils and high-fat meals, like soda and fries. In that scenario, fructose contributes to lipogenesis (fat creation) and raises triglycerides, especially when the liver is already overloaded. But fruit and honey are not the problem. In fact, they’re often part of the solution.
❤️ Final Thoughts: Sugar Is Not the Problem—Metabolic Dysfunction Is
Insulin resistance isn’t a carbohydrate problem—it’s a metabolism problem. And the solution is not to restrict sugar, but to repair the systems that allow you to burn it. That means eating enough, moving your body, lowering stress, sleeping deeply, and supporting your body with real food and real nutrients.
When you stop fearing sugar and start fueling your body the way it was designed to be fed, everything changes—your energy, your weight, your sleep, your cycles, your mood, your inflammation, your labs. It’s not about cutting more. It’s about coming back to balance.
🔁 Summary
Sugar doesn’t cause insulin resistance. A broken metabolism does.
Healing insulin resistance requires high-carb, low-fat, nutrient-rich eating—not keto.
Sugar supports the thyroid, liver, adrenals, and brain. It is not toxic when eaten in context.
PUFA, stress, under-eating, and muscle loss are the real culprits.
Stop blaming sugar. Start healing your metabolism. That’s how you reclaim your health.Why cutting carbs doesn’t fix the root cause—and why sugar is part of the solution
