Insulin resistance is one of the most widespread and health-harming conditions in the westernized world. A diagnosis of type 2 diabetes or pre-diabetes implies insulin resistance. However, insulin resistance starts long before it causes blood sugar to become elevated on lab tests, which means many people have insulin resistance and don't know it. Furthermore, insulin resistance has been found to cause inflammation and is now known to be a major contributor to heart disease and cancer. It's also implicated in polycystic ovarian syndrome and fatty liver disease.
In understanding insulin resistance it is first important to understand insulin/glucose physiology. A useful analogy is to think of insulin as the key that unlocks the cell allowing glucose to enter, where it can then be used for energy. Insulin resistance is a term used to describe a pathological state in which the cell does not allow glucose in despite the presence of insulin. It's like the call becomes “numb” to insulin.
So what causes insulin resistance? The most important contributor in our current food environment is saturated fat. Saturated fat is found primarily in animal products including meats, poultry, dairy, and eggs as well as in oils. When consumed, saturated fat builds up in our muscle cells. Scientists call this intramyocellular lipid. This toxic build-up of fat in our muscle cells causes them to become less sensitive to insulin, which means that instead of being brought into the cell where it can be used for energy, glucose instead stays out in the bloodstream where it accumulates and eventually causes damage.
Another contributor to insulin resistance is excessive intake of refined sugars, particularly fructose. Found in processed foods likes cakes and candy and in beverages like soda, refined sugars cause fat build-up and subsequent insulin resistance in the liver. A sedentary lifestyle also contributes to insulin resistance by making muscle cells less insulin-sensitive.
The good news is that insulin resistance is completely preventable and even reversible the majority of the time. Follow these basic lifestyle recommendations to keep yourself insulin sensitive:
1. Avoid saturated fats. This is not a popular suggestion as many people's favorite foods are rich in saturated fat. Fortunately following this advice is easy to do when following a whole foods, plant-based diet. When it comes to fats, opt for the whole plant versions like nuts and seeds. And no, oils are not healthy. They are a processed food and the most calorically dense food on the planet, so skip them, too.
2. Avoid refined sugars, especially soda and other sugar-sweetened beverages. As stated previously, these wreak havoc on your liver. They are also calorie rich while being nutrient poor. But don't make the mistake of avoiding all carbohydrates. Complex carbohydrates found in whole foods like brown rice and steel cut oatmeal are health-promoting. Also don't be afraid to eat whole fruit. Many people mistakenly believe that because fruit contains “sugar” it should be limited. In actuality, multiple studies have shown that fruit is protective against conditions like diabetes and obesity.
3. Stay active. Exercise readily increases the insulin sensitivity of your muscle cells. Try to do something active most days, preferably for 30-60 minutes. Break it up into smaller chunks if you need to.