
Insulin Resistance. Over time, too much added sugar in the diet (in addition to inactivity and obesity) can cause insulin resistance. Insulin regulates the amount of sugar that is in the bloodstream. One analogy is that insulin is like a key that opens the door to let blood sugar out of the bloodstream and into the cells where it can be converted to energy. When someone becomes resistant to insulin, the body produces more and more insulin in an effort to regulate blood sugar. This results in high levels of both glucose (sugar) and insulin in the blood. Insulin resistance can also result in excess fat storage in muscle and liver tissue.