Non-insulin-dependent diabetes mellitus is associated with obesity in 80 to 90%. The presence of obesity enhances insulin resistance, which increases the demands on insulin secretion and causes deterioration of glucose tolerance. Hyperinsulinism has some metabolic sequelae which increase the risk of the development and progression of atherosclerosis. Reduction of body weight is a basic therapeutic provision in obese diabetics. It results not only in better compensation of diabetes but also other metabolic parameters and blood pressure as it leads to a higher tissue sensitivity for insulin. This can delay the development of long-term complications of diabetes mellitus.