Obesity, like Type 2 diabetes, is an insulin-resistant state and plays an important role in the development of Type 2 diabetes. When a lean individual gains significant body weight, there is a marked decline in insulin sensitivity. However, the beta cell responds to the presence of the insulin resistance by augmenting its secretion of insulin and providing that the beta cell can maintain its high response of insulin secretion, glucose tolerance remains with-in a normal range. Over time (5-10 years) glucose tolerance deteriorates because the insulin resistance cannot be offset by the augmented pancreatic response and overt Type 2 Diabetes Mellitus is manifested.

Diet and exercise are the cornerstones of therapy in Type 2 Diabetes Mellitus. No pharmacological intervention will be successful in achieving normal blood glucose levels in the absence of diet and exercise. The obese diabetic who can lose and maintain a 20-30 lb. weight loss will achieve marked improvement in insulin sensitivity and a decrease in mean plasma glucose levels. This is true despite still being well above ideal body weight. Aerobic exercise is best for most patients. The goal is 30 minutes per day of some form of exercise that can be continued indefinitely. Cardiovascular assessment is required prior to starting an exercise program in patients over the age of 40 years