Think your risk of type 2 diabetes is near zero because your weight is in the normal range? Not quite. “The most important thing you can do to lower your risk of type 2 diabetes is to avoid weight gain and lose excess weight,” says JoAnn Manson, chief of preventive medicine at Brigham and Women’s Hospital in Boston. That’s because roughly nine out of ten people with diabetes are overweight or have obesity. But weight isn’t the whole ballgame.