What Causes Insulin Resistance?

Updated: Jul 1, 2021

Insulin resistance results in type 2 diabetes, but what causes insulin resistance?

Graphic by @katrin.kristin


After a meal, your blood sugar levels rise - a NORMAL response. Your pancreas then produces insulin which signals your muscle and liver cells to take in glucose for energy or to be stored for later. Many often blame carbs for insulin resistance. But what is insulin resistance?


Insulin resistance is impaired ability of liver and muscle cells to respond to insulin.

Saturated fats are the main culprit for inducing insulin resistance. They get inside your liver and muscle cells and overwhelm cells into not being able to communicate effectively with insulin and disrupt the insulin signaling pathway. Saturated fats are mainly found in animal products like meat, poultry, fish, shellfish, and especially dairy products, but are also high in some plant foods like coconut oil and palm oil.


Mono- and poly-unsaturated fatty acids on the other end are beneficial for your health and should be incorporated in your diet daily. However, it is important to keep into perspective that all fatty foods have some saturated fat and with higher intake of fat, saturated fat intake may also increase. So make sure to keep saturated fat intake low.


Plant-based whole foods are generally very low in saturated fats. Replacing animal foods with plant-based foods can help reduce insulin resistance. Complex carbohydrates with high fiber and low saturated fat help protect you from insulin resistance. But what about refined sugar?


Refined sugar doesn’t directly have as big of impact. It is still however problematic as it can be inflammatory, lead to excess calories and production of fat in liver. Excess calories increase fat storage. This increases fatty acids released in blood stream which can enter muscle and liver cells and hence initiating the process of insulin resistance. Fatty liver also induces insulin resistance.


Other two factors that also play a role in insulin resistance are exercise (or lack of) and stress. Exercise not only can help with reduction of body fat which would help reduce insulin resistance, but it also directly helps overcome insulin resistance in muscle cells. Stress has a hormonal effect in our body through the “fight or flight response” which increases stress hormones and can induce insulin resistance.


Check out the Plant Prescription Podcast episode where Cyrus Khambatta, PhD and Robby Barbaro, MPH from Mastering Diabetes talk about the importance of diet and clear up misconceptions concerning diabetes and insulin resistance.


References:

  1. Am J Clin Nutr 2009: A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-week clinical trial.

  2. Nutr Metab Cardiovasc Dis 2013: Vegetarian diets and incidence of diabetes in the Adventist Health Study-2.

  3. J Geriatr Cardiol 2017: A plant-based diet for the prevention and treatment of type 2 diabetes.

  4. IJDRP 2019: Treatment and remission of symptoms in type 1 diabetes with a nutrient-dense, plant-rich (NDPR) diet: case studies.

  5. IJDRP 2020: Treatment of type 2 diabetes mellitus with a whole-food, plant-based diet.

  6. BMJ Open Sport Exerc Med 2017: Update on the effects of physical activity on insulin sensitivity in humans.

  7. J Epidemiol 2016: Investigation of the Relationship Between Chronic Stress and Insulin Resistance in a Chinese Population.

  8. J Endocrinol 2013: Acute psychological stress results in the rapid development of insulin resistance.