It is estimated that 40% of adults in the U.S. ages 18-44 are insulin resistant, up from about 22% only two decades ago.1 Since this condition is so prevalent, it’s important to know your level of risk and what you can do about it.  

What is insulin resistance?

Insulin is made in the pancreas and released in response to carbohydrates in the diet that convert to sugar. Insulin regulates blood sugar levels by helping glucose enter cells for energy and lowering sugar in the blood. Insulin resistance or impaired insulin sensitivity is a condition where your body's cells become less responsive to the hormone insulin.

When cells become resistant, glucose stays in the bloodstream instead of being transported into the cell, leading to elevated blood sugar levels. The result is that cells don’t have the nutrients they need to create energy for working muscles, the brain, other crucial organs, and metabolic processes. At the same time, the pancreas may continue to produce insulin, raising those levels in the bloodstream and eventually damaging the beta cells in the pancreas that produce insulin.  

Insulin resistance has numerous metabolic consequences if left untreated. Most commonly, it is thought to precede prediabetes or type 2 diabetes by 10-15 years in some individuals.1

Symptoms of insulin resistance

In the beginning stages of insulin resistance, there may or may not be noticeable symptoms. Some individuals are only aware of their condition when getting a blood test that includes fasting blood sugar, HOMA-IR (a test for insulin resistance), hemoglobin A1c (HbA1c; a test for long-term blood sugar control), and insulin levels. As it progresses, many will notice changes in their lipid levels, especially elevated triglycerides, but they might also see high LDL, total cholesterol, and/or inflammatory biomarkers – all signs that the body is not metabolizing and clearing sugar properly. 

As far as physical symptoms, the most classic ones include fatigue, increased thirst, frequent urination, and weight gain with weight loss difficulty. Some also experience headaches, tingly extremities, blurred vision, irregular menstrual cycles, delayed healing of wounds, and increased infections. 

These symptoms are most often experienced in later stages – when the condition has progressed to type 2 diabetes. Many of these associated conditions can lead to permanent damage if left untreated. For example, blurred vision can be a result of elevated glucose levels, causing damage to the small blood vessels in the back of the eyes that can lead to vision loss. Also, delayed wound healing and infections can lead to serious metabolic disruptions, sepsis, and gangrene. 

Risk factors for insulin resistance

Insulin resistance can be caused by various lifestyle factors, including poor diet, obesity, physical inactivity, and hormonal imbalances, but also can be a result of genetics and certain medications. It is important to know that if you become insulin resistant, it can be temporary or chronic – meaning it can be reversed as so many of its biggest risk factors are modifiable. 

Keep in mind that many of the factors associated with insulin resistance are similar to those of metabolic syndrome. In fact, insulin resistance is frequently seen in individuals with metabolic syndrome (MetS), the latter of which is diagnosed if three or more of the below factors are present:

  • A waistline of over 40 inches for men and over 35 inches for women
  • Elevated blood pressure of 130 over 85 or above 
  • Fasting glucose levels of 100 milligrams per deciliter (mg/dL) or higher
  • Triglyceride levels of 150 mg/dL or higher
  • HDL (the good cholesterol) less than 50 mg/dL in women and less than 40 mg/dL in men

It is important to note that insulin resistance can start in young kids and teens; it is not a concern just for adults. Girls are at greater risk than boys, possibly due to earlier puberty.2 Other risk factors for insulin resistance in children can include accumulation of belly fat, poor diet, inactivity, family history, children being born to women who had gestational diabetes or were undernourished during pregnancy, low birth weight, and certain medications. 

Early screening and diagnosis by your health-care professional are crucial in associated conditions from impaired insulin sensitivity, including metabolic syndrome, dyslipidemia, endothelial dysfunction, nonalcoholic fatty liver disease, and polycystic ovary syndrome. If not addressed, insulin resistance can progress to prediabetes or type 2 diabetes, which can contribute to complications that include eye health issues, heart disease, kidney disease, and stroke.

Thorne’s Advanced Health Panel and Essential Health Panel are two comprehensive in-lab blood tests to help you learn your glucose, insulin, cholesterol, inflammatory markers, HOMA-IR, and HbA1c levels. 

What you can do

The key to reversing or preventing insulin resistance is making cells more sensitive to insulin. The top recommendations are diet and lifestyle changes:

  • Dietary: For many, the Mediterranean-style diet, which focuses on vegetables, lean protein, and healthy fats, is very effective. For others, a ketogenic diet that restricts carbohydrates may be suggested for weight loss and improvements in insulin resistance.3 No matter your dietary style, limit processed foods, sugary drinks, and saturated fats.
  • Regular exercise: Aim for at least 30 minutes of exercise at a moderate intensity most days of the week. Exercise doesn't have to be in a super structured gym setting – get creative by finding ways to increase your heart rate and break a sweat. If you are a beginner to exercise, start slowly and steadily increase your duration and intensity to avoid injury. For those who already get 30 minutes, switch up your routine. Add weightlifting, join a fitness class or running group, hire a trainer to build a program, or get outside more.
  • Manage your weight: If you have excess body fat, losing 5% of your body weight can improve insulin sensitivity, reduce your risk for diabetes, and improve your HbA1c levels. For a 200-pound person with excess body fat, that's 10 pounds, a manageable number when adding exercise, following a diet plan, getting enough sleep, and reducing stress. Not coincidentally, weight loss also helps to improve sleep, energy, mood, libido, and more.4
  • Maximize your macronutrients: Think about your total calories and what foods you’re consuming! Too many carbohydrates or not the right types will impact glucose and lipid levels. Protein is a macronutrient that can help maintain satiety and muscle mass in a calorie deficit, and fiber can help to maintain healthy blood sugar levels. Meal timing and the order in which you consume foods can also play a role.
  • Consider a supplement: A nutritional supplement might help support your healthy lifestyle changes. Some to consider:
    • Diabenil contains botanicals and nutrients that offer comprehensive support for maintenance of normal blood sugar levels. They also help support healthy nerves, blood vessels, eyes, and kidneys.*
    • Chromium Picolinate provides the chromium often lacking in daily diets. Studies suggest chromium helps maintain already normal glucose levels and insulin sensitivity and can assist in weight management.*
    • Berberine helps to maintain healthy cholesterol and blood sugar levels, promotes GI microbial balance, and supports healthy metabolism.*
    • Metabolic Health contains well absorbed curcumin and bergamot phytosomes that help to maintain a healthy weight by helping to suppport fat metabolism, optimal cholesterol, and blood sugar levels.*
    • Thorne’s Weight Management Bundle contains three supplements that help maintain a healthy weight and promote optimal metabolism – Metabolic Health, Super EPA, and FloraMend Prime Probiotic®.*

References

  1. Freeman AM, Acevedo LA, Pennings N. Insulin resistance. In: StatPearls. StatPearls Publishing; 2024.
  2. Lee JM, Okumura MJ, Davis MM, et al. Prevalence and determinants of insulin resistance among U.S. adolescents: a population-based study. Diabetes Care. 2006;29(11):2427-2432.
  3. Paoli A, Bianco A, Moro T, et al. The effects of ketogenic diet on insulin sensitivity and weight loss, which came first: The chicken or the egg? Nutr. 2023;15(14). doi:10.3390/nu15143120
  4. Ryan DH, Yockey SR. Weight loss and improvement in comorbidity: Differences at 5%, 10%, 15%, and over. Curr Obes Rep. 2017;6(2):187-194.