Chronic exposure to refined carbohydrates and simple sugars can cause elevated levels of insulin, which drives glucose levels down. This can result in hypoglycemia (low blood sugar). Over time, tissues may become less sensitive to insulin and as a result glucose cannot enter the cells as easily. This means more glucose in the bloodstream and a greater tendency to convert it into fat instead of energy. Elevated insulin levels (hyperinsulinemia) cause the body to have difficulty breaking down fat also.
Indications of hyperinsulinemia include weight gain (especially around the waste producing the apple shape, not the pear shape), increased blood pressure and cholesterol. When several factors are present, it may be called Syndrome X. Testing for elevated insulin levels can be an important step toward better health, and the prevention of diabetes and chronic disease processes later in life.
Insulin is primarily a storage hormone. Its main purpose is to store nutrients in your body. However, insulin stores more than just glucose. It works in the same way with protein and fat.
- Insulin increases the activity of lipoprotein lipase (LPL). When it’s expressed in adipose tissue (body fat), this enzyme promotes the storage of fat.
- Insulin inhibits the action of hormone sensitive lipase, the enzyme responsible for breaking down stored fat and preparing it for use as energy.
- Insulin also activates an enzyme called acetyl co-enzyme A carboxylase , which, along with fatty acid synthase, is responsible for converting carbohydrate into fat.
High levels of insulin make it less likely that your body will use stored fat as a fuel source. Some evidence that this is the case comes from a recent study completed at England’s Loughborough University. Eight subjects received either a high or low glycemic index meal three hours prior to exercise. Each meal contained identical amounts of protein, carbohydrate and fat. Insulin levels following the meal containing the high glycemic index carbohydrate increased by a massive 1000% after just 15 minutes.