Dr. Mehmet Oz
Insulin resistance may be most closely associated with diabetes, but according to Dr. Jay Lombard and Peter Morgan Kash, it's also the culprit behind many of the diseases plaguing Americans, including heart disease, cancer, depression and Alzheimer's. Dr. Oz talks with Dr. Lombard and Peter, co-authors of Freedom from Disease, about the role of insulin in the body and how to keep insulin levels in check for good health.

Insulin is a hormone that helps the body use glucose, or blood sugar. When sugar intake is too high, Dr. Lombard says insulin and glucose levels get out of balance and glucose builds up in the blood, leading to insulin resistance and inflammation linked to various diseases. "Your entire metabolism is thrown off kilter. ... Insulin resistance is not just diabetes—it's a multiconverging pathway for a multitude of disease processes," Dr. Lombard says.

Insulin resistance can be prevented and possibly reversed by eating a nutritious diet, maintaining a healthy body weight, reducing stress and getting regular exercise, Dr. Lombard and Peter say. The key is to control insulin levels and to keep the entire body healthy before medical intervention becomes necessary. "We're treating diseases at the end stages of disease as opposed to early stages of disease," Dr. Lombard says.