Understanding What Is Insulin Resistance

Insulin resistance is at the core of many chronic conditions, including type 2 diabetes, PCOS, obesity, heart disease, and even Alzheimer’s. Yet, it’s often misunderstood as simply a “sugar problem."

In this article, we break down insulin resistance so you have the complete picture of how it affects health. It's not just a sugar, but a more complex health issue that causes many other diseases.

🔍 What Is Insulin Resistance?

Insulin is a hormone made by the pancreas that helps your cells absorb glucose (sugar) from the blood to use for energy or storage.

Insulin resistance occurs when your cells become less responsive to insulin. The pancreas produces more insulin to compensate, resulting in elevated insulin levels (hyperinsulinemia) and, eventually, high blood sugar.
Over time, this can exhaust your pancreas and lead to type 2 diabetes, but symptoms can begin long before that.

🚨 Insulin Resistance Symptoms

• Fatigue after meals
• Constant hunger or sugar cravings
• Belly fat
• Brain fog
• Skin tags or dark patches on the neck
• Irregular menstrual cycles (in women)
• High triglycerides, low HDL cholesterol
• Elevated fasting insulin or glucose

🔑 The 9 Root Causes of Insulin Resistance (Beyond Glucose)

1. Chronic Inflammation

• Pro-inflammatory cytokines interfere with insulin receptor signaling.
• Common in autoimmune disease, gut imbalances, and toxin overload

2. Processed Seed Oils & Omega-6 Overload

• Sunflower, corn, soybean, and canola oils are high in omega-6 polyunsaturated fatty acids (PUFAs), which are unstable and prone to oxidation.
• When consumed in excess, these oils incorporate into cell membranes, making them more rigid and inflamed.
• This disrupts the structure and function of insulin receptors on the cell surface — making insulin signaling less effective.
• Over time, the altered membrane composition contributes to chronic inflammation and cellular dysfunction, both of which drive insulin resistance.

3. Sleep Deprivation

• Reduces insulin sensitivity in as little as one night
• Increases cortisol and hunger hormones

4. Chronic Stress & High Cortisol

• Cortisol raises blood sugar and blocks insulin action.
• Constant fight-or-flight mode keeps insulin elevated.

5. Environmental Toxins (Endocrine Disruptors)
Arsenic is often found in:
Contaminated groundwater (especially in well water), rice and rice products (rice absorbs more arsenic than most crops), some seafood (due to water contamination), and pesticide residues on non-organic produce.

Cadmium is commonly found in:
Cigarette smoke (both first-hand and second-hand), industrial pollution and contaminated soil, certain grains and leafy greens grown in polluted areas, and organ meats like liver and kidney (if the animal was exposed).

Both arsenic and cadmium are heavy metals that build up in the body over time. They can damage the pancreas, impair insulin secretion, and promote inflammation and oxidative stress — all of which contribute to insulin resistance.

🚫BPA, phthalates, pesticides
Reduce exposure to BPA, phthalates, pesticides, and heavy metals as they act as endocrine-disrupting chemicals (EDCs)

• These toxins can bind to hormone receptors, confuse cellular messages, and alter insulin sensitivity at the receptor level.
• BPA and phthalates mimic estrogen and disrupt insulin signaling, contributing to weight gain, blood sugar spikes, and metabolic dysfunction.
• These toxins are often stored in fat tissue, making them hard to eliminate without liver support, detoxification, and fat loss.

Chronic exposure to these chemicals quietly promotes insulin resistance — even in people who eat well or have no family history of diabetes.

6. High Fructose Load

• Fructose is metabolized in the liver.
• Excess fructose (especially from sodas, syrup, processed snacks) leads to fatty liver and insulin resistance.

7. Low Muscle Mass & Sedentary Lifestyle

• Muscle tissue is the main site for glucose uptake.
• Less muscle = more circulating glucose and insulin.

8. Micronutrient Deficiencies

Micronutrients play essential roles in supporting insulin production, sensitivity, and glucose metabolism. When key vitamins and minerals are lacking, insulin cannot function effectively at the cellular level.
Even mild deficiencies in these nutrients can impair insulin action and worsen metabolic outcomes. A diet lacking in whole, nutrient-dense foods increases the risk of deficiency.

• Vitamin D receptors are found on pancreatic beta cells, which produce insulin. Without enough vitamin D, these cells may underperform or become dysfunctional. Vitamin D also enhances insulin sensitivity in both muscle and fat tissue, allowing cells to respond more effectively to insulin. Low vitamin D levels are linked to Impaired insulin secretion and higher fasting glucose and insulin levels.
• Magnesium: Involved in over 300 enzymatic reactions, magnesium plays a critical role in insulin receptor sensitivity. Low levels are common in people with insulin resistance and type 2 diabetes.
• Zinc: Supports insulin synthesis and storage in the pancreas, and also acts as an antioxidant.
• Chromium: Enhances the action of insulin and supports glucose uptake into cells.
• Omega-3 fatty acids: Help reduce inflammation and improve insulin signaling in cell membranes.

9. Impaired Insulin Production

Sometimes the issue isn’t just insulin resistance — it’s that the pancreas cannot produce enough insulin in the first place. This may result from:

• Pancreatic beta-cell burnout due to years of overproduction caused by high sugar intake or insulin demand
• Autoimmune destruction of insulin-producing beta cells (as seen in type 1 diabetes)
• Chronic inflammation that impairs pancreatic tissue
• Toxin exposure (e.g., BPA, heavy metals, mold) that damages the pancreas
• Nutrient deficiencies (especially zinc, magnesium, B vitamins, and vitamin D)

Supporting pancreatic health is essential for long-term insulin balance.

• Eat anti-inflammatory, antioxidant-rich foods (e.g., berries, leafy greens, turmeric, ginger)
• Include healthy fats (such as avocados, olive oil, and flaxseeds) to reduce inflammation.
• Prioritize magnesium, zinc, and B-vitamins (from leafy greens, seeds, nuts, and whole foods)
• Avoid refined sugars, trans fats, and excessive alcohol — all of which stress the pancreas.
• Add gentle fermented foods to support gut and immune health (which indirectly protects the pancreas)
• Rest your pancreas with meal spacing.

Insulin Resistance and Other Health Issues

🧠 Constipation & Insulin Resistance

Insulin resistance slows gut motility by affecting nerve signals and muscle contractions in the colon. It also impacts thyroid function, which regulates digestive speed. Here's how:

• Insulin resistance can suppress the conversion of T4 (inactive thyroid hormone) to T3 (the active form), reducing thyroid efficiency.
• T3 plays a crucial role in maintaining gut motility — the rhythmic muscle contractions that propel food and waste through the intestines.
• When thyroid function slows, so does digestion, often resulting in sluggish bowels and constipation, even when fiber is sufficient.
• This creates a feedback loop: poor thyroid function worsens constipation, and chronic constipation exacerbates inflammation, which in turn further impairs insulin sensitivity.
• Constipation worsens insulin resistance by increasing inflammation, creating gut dysbiosis, and overwhelming the liver’s detox workload.

They also share root causes such as low magnesium, stress, poor hydration and fiber intake, estrogen dominance, and Liver overload.

When you experience constipation, it often signals a more profound metabolic imbalance. Addressing it helps improve blood sugar regulation, hormone balance, and inflammation.

🚻 Insulin Resistance & Infertility

Insulin resistance is a major — and often overlooked — driver of infertility, especially in women but also in men.
In women, high insulin levels

• Disrupt the delicate balance of reproductive hormones:
• Increases androgens (like testosterone), which can prevent ovulation
• Worsens PCOS, one of the leading causes of infertility
• Impairs egg quality and regular menstrual cycles

In men, insulin resistance contributes to:

• Lower testosterone
• Increased estrogen
• Poor sperm quality and motility

Insulin resistance also increases inflammation and oxidative stress, which damages reproductive tissues and impairs embryo implantation.
Restoring insulin sensitivity improves hormone balance, ovulation, and overall fertility outcomes.

🔄 Insulin Resistance & Hormonal Imbalances

Insulin resistance disrupts the balance of several key hormones in both men and women:

• Estrogen and progesterone: High insulin levels can lead to estrogen dominance and reduced progesterone levels, disrupting menstrual cycles and affecting mood.
• Testosterone: In women, insulin stimulates the ovaries to produce excess testosterone, contributing to PCOS. In men, insulin resistance is linked to lower testosterone levels.
• Leptin: Chronic high insulin levels can lead to leptin resistance, impairing satiety signals and contributing to weight gain and increased cravings.
• Cortisol: Insulin resistance and chronic stress often go hand in hand, creating imbalances that worsen both conditions.
• Thyroid hormones (T3, T4): As seen above, insulin resistance can impair the conversion of T4 to T3, reducing thyroid function and slowing metabolism.

These hormonal shifts impact metabolism, fertility, mood, weight regulation, and energy levels.

🫀 Insulin Resistance & Non-Alcoholic Fatty Liver Disease (NAFLD)

NAFLD occurs when excess fat builds up in the liver of people who drink little or no alcohol, and it’s strongly tied to insulin resistance.

• Insulin resistance causes the liver to store more fat, particularly from excess glucose and fructose.
• At the same time, insulin blocks fat burning (lipolysis), so fat accumulates in liver cells.
• Over time, this fat buildup causes inflammation, liver cell damage, and fibrosis — which can progress to non-alcoholic steatohepatitis (NASH) or even cirrhosis.

NAFLD often has no symptoms but is now the most common liver condition globally — especially in those with obesity, type 2 diabetes, or metabolic syndrome.
Restoring insulin sensitivity is the most critical intervention for reversing NAFLD and protecting long-term liver health.

🧬 Insulin Resistance & Cholesterol

Insulin resistance affects cholesterol in several key ways — increasing the risk of heart disease and metabolic syndrome:

• It raises triglycerides by stimulating fat production in the liver.
• It lowers HDL cholesterol (the "good" cholesterol), which helps remove excess cholesterol from the bloodstream.
• It increases the number of small, dense LDL particles — these are more inflammatory and more likely to penetrate arterial walls than larger LDL particles.
• High insulin levels also promote the oxidation of LDL cholesterol, making it more susceptible to damage and increasing the risk of plaque formation.

Together, these lipid patterns are known as atherogenic dyslipidemia, and they're a hallmark of insulin resistance. Improving insulin sensitivity not only stabilizes blood sugar but also optimizes lipid profiles and lowers cardiovascular risk

🧈 Insulin & Weight Gain

Insulin is an anabolic hormone, meaning it promotes the building and storage of tissue. One of its key roles is to store excess energy, particularly as fat.

• When glucose is in excess and glycogen stores are full, insulin signals the body to convert the extra glucose into fat (lipogenesis)
• It also inhibits lipolysis, which is the breakdown of stored fat, meaning you can’t burn fat easily when insulin is high.
• This is why frequent spikes in insulin (from refined carbs, snacking, or stress) make it hard to lose weight, even with exercise.

Insulin essentially acts as a "storage switch," keeping the body in a fat-storing rather than a fat-burning state. Reducing insulin spikes through balanced meals, fasting windows, or improved sensitivity can help shift your body from storing to burning fat.

💊 Insulin & Sodium

Insulin not only regulates glucose, but it also influences sodium retention. When insulin levels are high, the body shifts into a "storage and conservation" mode, including holding onto sodium. Here's why:

• When insulin levels are high, the kidneys are signaled to reabsorb more sodium into the bloodstream rather than excrete it in the urine.
• This sodium retention can lead to water retention, increased blood volume, and ultimately higher blood pressure.
• Over time, chronic hyperinsulinemia can contribute to hypertension, especially when combined with low magnesium or potassium levels.

This is one reason why insulin resistance and high blood pressure often show up together. Supporting insulin sensitivity helps restore proper fluid balance, reduces water retention, and lowers the risk of hypertension.

✅ And the reverse is also true: Balancing electrolytes — primarily by increasing magnesium and potassium while reducing excess sodium — can help improve insulin sensitivity. These minerals support healthy cellular function, reduce inflammation, and restore normal insulin signaling.

🍽️ Insulin, Hunger & Cravings Cycle

Insulin also plays a significant role in regulating appetite and cravings.

• When insulin spikes (from a high-sugar or high-carb meal), blood sugar levels rise quickly, but then fall soon after.
• This fall triggers hunger hormones like ghrelin and leptin, making you feel hungrier, even if you've recently eaten.
• High insulin also blocks the brain’s ability to register satiety by interfering with the function of leptin, the hormone that signals fullness to the brain. When insulin is chronically elevated, it promotes leptin resistance. Additionally, insulin disrupts signaling in the hypothalamus, the part of the brain that regulates appetite and energy balance, making it harder to feel satisfied after meals, so you keep craving food, especially sugar or carbs.
• Chronic high insulin can even desensitize dopamine receptors, making you crave more food to feel pleasure.
• This leads to a rollercoaster of eating, glucose spike, and craving, a key driver of emotional eating and weight gain.

Stabilizing blood sugar and reducing insulin spikes breaks this cycle — restoring normal hunger cues, energy, and food freedom.

🦶 Insulin Resistance, Diabetes & Foot Health

Feet are especially vulnerable in people with diabetes and insulin resistance due to:

• Poor blood circulation: Chronically high insulin levels damage the endothelium (the lining of blood vessels), impairing nitric oxide production. This reduces blood vessel flexibility and limits blood flow, particularly to smaller extremities, such as the feet.
• Over time, this contributes to oxygen and nutrient deficiencies in tissues, resulting in slower wound healing and an increased risk of ulcers.
  Poor blood circulation (caused by vascular damage) reduces the delivery of oxygen and nutrients to the feet.
• Nerve damage (peripheral neuropathy) can dull pain sensation, making it easier to miss injuries or infections.
  Weakened immunity and slow wound healing increase the risk of ulcers, infections, and, in severe cases, amputation.

Even without diabetes, insulin resistance alone can lead to early signs of neuropathy and circulation issues — often felt as tingling, numbness, cold feet, or burning pain.
Taking care of your blood sugar and insulin sensitivity is one of the most powerful ways to protect your feet, especially as you age.

🩹 Insulin, Wound Healing, Oxidative Stress & Vision

Prolonged healing and vision problems are common in diabetes and insulin resistance:

• High insulin and blood sugar damage small blood vessels (microvascular damage), reducing oxygen and nutrient delivery to tissues. This impairs the body’s ability to repair wounds.
• High glucose levels also impair immune cell function, increasing the likelihood of infections and further slowing the healing process. When glucose levels remain elevated, immune cells such as neutrophils and macrophages become less effective at migrating to injury sites, engulfing pathogens (phagocytosis), and releasing proper signaling molecules. Additionally, high glucose levels create an inflammatory environment that disrupts immune balance, making the body more susceptible to chronic infections and impaired wound healing.
  In the eyes, insulin resistance and high blood sugar damage the fragile retinal blood vessels, leading to blurry vision, retinopathy, and, eventually, vision loss if left unmanaged.
• Oxidative stress and inflammation from chronic high insulin also accelerate tissue aging, scarring, and poor regeneration. This occurs because elevated insulin levels increase the production of reactive oxygen species (ROS) within cells, particularly in mitochondria. ROS are unstable molecules that damage proteins, DNA, and cell membranes. At the same time, high insulin levels reduce the body’s natural antioxidant defense systems (such as glutathione). This happens because insulin resistance promotes chronic low-grade inflammation and oxidative stress, which depletes glutathione faster than it can be replenished.
• Additionally, insulin resistance impairs nutrient absorption and mitochondrial function, both of which are crucial for the synthesis and recycling of glutathione—the body’s master antioxidant, tipping the balance toward oxidative stress.
• The higher the insulin levels, the more free radicals accumulate, leading to inflammation, tissue breakdown, and an increased risk of disease.

These complications don’t only occur in diabetes. Insulin resistance alone, even in the presence of normal glucose levels, can lead to these issues over time.

🧖 Insulin Resistance & Skin Health

Insulin resistance can also manifest through the skin, often long before a diagnosis of diabetes. Some of the most common skin-related symptoms include:

• Acanthosis nigricans: Dark, velvety patches on the neck, underarms, or groin caused by high insulin, which stimulates excessive skin cell growth.
• Skin tags: Small, benign growths commonly found in areas of friction, triggered by elevated insulin levels.
• Acne and oily skin: Insulin increases androgen levels, which stimulate sebaceous (oil) glands and can lead to clogged pores.
• Delayed wound healing: High insulin impairs immune function and blood flow, slowing skin repair.
• Itching and dryness: Circulatory and inflammatory changes associated with insulin resistance can impact skin hydration and integrity.

Skin symptoms are often visible indicators of deeper metabolic dysfunction, and can improve dramatically with better blood sugar and insulin regulation.

🧠 Insulin, Brain Fog, Anxiety & Mental Fatigue

Insulin isn’t just about energy — it’s deeply connected to how the brain thinks, remembers, and feels. Here's how insulin resistance affects cognitive and emotional function:

• The brain relies on a steady supply of glucose, but insulin resistance disrupts glucose uptake, especially in the hippocampus (which is linked to memory, learning, and mood).
• This results in brain fog, memory issues, poor focus, and anxiety, even if blood sugar appears normal.
• Chronic high levels of insulin and glucose trigger neuroinflammation, which damages neurons and slows brain signaling.
• Over time, this can contribute to depression, cognitive decline, and Alzheimer’s (also called type 3 diabetes).
• Additionally, energy crashes from poor glucose control can lead to mental exhaustion, irritability, and low motivation.

Improving insulin sensitivity often brings clarity, focus, and emotional stability — not just better blood sugar.

📌 Can You Have Insulin Resistance Without Diabetes?

Absolutely, and this is a critical point.
Insulin resistance can exist for years or even decades before a person is diagnosed with type 2 diabetes. During this time, it can quietly drive many other chronic conditions, even if blood sugar appears "normal" on standard tests.
Conditions strongly linked to undiagnosed insulin resistance include:

• PCOS (Polycystic Ovary Syndrome)
• Heart disease and high blood pressure
• Cognitive decline and Alzheimer’s (type 3 diabetes)
• Obesity and stubborn weight gain
• Fatty liver disease
• Hormonal imbalances, infertility, and chronic fatigue
• Digestive issues and chronic constipation

You do not have to be diabetic to suffer the consequences of insulin resistance. That’s why early detection and lifestyle change are so powerful; they stop disease before it fully develops.

🧪 We Monitor Insulin Instead of Glucose

Monitoring insulin provides an earlier warning than glucose alone does.

• Blood glucose levels may remain "normal" for years, even as insulin levels increase, because the body compensates by producing more insulin.
• By the time glucose becomes elevated, insulin resistance has often been present for 5–10 years.

Testing fasting insulin or a glucose-insulin curve can reveal problems much earlier than glucose or A1C alone, which allows early intervention before complications like diabetes, PCOS, or heart disease develop.

🥦 How Reverse Insulin Resistance

Insulin resistance is a systemic condition rooted in cellular overload, mitochondrial dysfunction, and inflammatory signaling. Reversing it requires supporting metabolic flexibility — the body’s ability to switch efficiently between using fat and glucose for energy. Below are practical, evidence-informed strategies that target the core mechanisms of insulin resistance.

✅ 1. Nourish Cellular Function with Targeted Nutrition
Emphasize fiber- and protein-rich meals to improve satiety, slow digestion, and modulate glucose absorption.
Include low-glycemic carbohydrates such as sweet potatoes, lentils, legumes, and berries, which deliver glucose more gradually and protect against sharp insulin spikes.
Incorporate omega-3 fatty acids (found in chia seeds, flaxseeds, walnuts, and fatty fish) to reduce inflammation and support insulin receptor sensitivity.
Add fermented foods (such as sauerkraut, kimchi, kefir) and bitter greens (like dandelion, arugula, and chicory) to stimulate bile flow and enhance gut-liver axis function — both crucial in reversing metabolic dysfunction.

✅ 2. Reduce Exposure to Dietary and Environmental Stressors
Avoid ultra-processed foods, which are often high in refined flours, added sugars, and emulsifiers, and which contribute to gut dysbiosis and systemic inflammation.
Minimize refined sugars and high-fructose syrups, which promote liver fat accumulation and disrupt insulin signaling.
Eliminate or reduce intake of refined vegetable oils (e.g., corn, soybean, sunflower) and deep-fried foods, which introduce oxidized fats and contribute to lipid imbalance.
Limit exposure to endocrine-disrupting chemicals (found in some plastics, food packaging, and cosmetics) that can interfere with insulin regulation and hormone balance.

✅ 3. Move More — Strategically and Consistently
Engage in resistance training, which improves insulin sensitivity by increasing muscle mass — a primary site for glucose disposal.
Incorporate regular walking or aerobic activity, which activates muscle glucose uptake independently of insulin.
A simple routine of 10–15 minutes of light movement after meals (e.g., walking, gentle stretching) can significantly lower postprandial glucose and insulin levels.

✅ 4. Prioritize Sleep and Stress Recovery
Aim for 7–9 hours of restorative sleep per night. Sleep deprivation is strongly associated with increased insulin resistance, elevated cortisol levels, and dysregulation of appetite.
Incorporate nervous system-regulating practices such as diaphragmatic breathing, mindfulness meditation, grounding, or journaling to reduce chronic stress.
Lowering cortisol not only improves insulin signaling but also reduces cravings and helps restore natural hunger–fullness cues.

These lifestyle strategies do not serve as short-term fixes, but as foundational shifts to restore metabolic balance. When applied consistently, they address the root physiological drivers of insulin resistance — not just its symptoms — and may prevent progression to diabetes, cardiovascular disease, and other metabolic conditions.

💡 Conclusion

Insulin resistance involves multiple organs and systems; it is not just about sugar. Heal your inflammation, support your liver, nourish your cells, and restore insulin sensitivity.

Disclaimer

At FOODHEAL, we believe in education that empowers you to take charge of your health through food, movement, and conscious living. This article and the information within it are offered as educational content only.

Resources

• Insulin resistance and cardiovascular
• PCOS and insulin resistance
• Insulin resistance and vision
• Insulin resistance and infertility