Why is it that right after you eat that sweet desert, handful of dried fruit or heaping helping of mashed potatoes, your hunger rebounds with a vengeance?
Eating carbohydrates causes blood glucose levels to rise. It’s best when these levels rise slowly as is the case with a complex carbohydrate source, as in whole grains and veggies. However, it rises quickly if it is from simple carbohydrates, such as sugary treats, white pasta, fruit or even yogurt.
Glucose has little use while in circulation in the blood. In fact, high blood glucose, or hyperglycemia, is toxic and dangerous if it’s too high for too long. As blood glucose levels rise, so does the risk of hyperglycemia. This in turn causes the insulin secretion to rise, signaling body cells to absorb glucose, removing it from circulation.
Simple carbohydrates deliver glucose very rapidly into the bloodstream resulting in a fast rise in insulin. Complex carbohydrates take longer to digest and absorb and thus result in slower insulin secretion. So, the rate of glucose rise is directly correlated to the rate of insulin-mediated glucose decline. Recall that the rate of glucose depletion we experience can be a primary driver of hunger. The more rapid spike up — and down — in blood glucose, the more likely we are to experience a false sense of hunger shortly after a meal.
Media and advertising suggest we should eat carbohydrate-rich meals often. They reason that this constant flow of carbohydrates is the best way to regulate your metabolism and prevent hypoglycemia, or low blood glucose. Truth is, unless you are diabetic this is exactly the opposite of what your body needs to properly regulate metabolism and hunger.
Complex carbohydrates are a suitable fuel for sustained physical work, endurance sports training or competition. For all other times, it would suit our metabolism and mitochondria best to avoid insulin spikes. The ill effects of chronically elevated insulin are directly correlated with the usual host of chronic health conditions, including diabetes, obesity and cardiovascular disease.