What is it? Type 2 diabetes used to be called adult-onset diabetes or noninsulin-dependent diabetes. It is the most common type of diabetes in the U.S. Type 2 diabetes is a disease in which blood sugar levels are above normal. High blood sugar is a major cause of early death, heart disease, kidney disease, stroke, and blindness. How is it linked to overweight? More than 80 percent of people with type 2 diabetes are overweight. It is not known exactly why people who are overweight are more likely to suffer from this disease. It may be that being overweight causes cells to change, making them less effective at using sugar from the blood. This then puts stress on the cells that produce insulin (a hormone that carries sugar from the blood to cells) and makes them gradually fail. What can weight loss do? You can lower your risk for developing type 2 diabetes by losing weight and increasing the amount of physical activity you do. If you have type 2 diabetes, losing weight and becoming more physically active can help you control your blood sugar levels. Losing weight and exercising more may also allow you to reduce the amount of diabetes medication you take.