Two reports released this week shed light on the current state of type 2 diabetes in this country, and their conclusions are promising and sobering. First, the good news: An article in The New England Journal of Medicine shows that rates of diabetes-related problems like heart attack, stroke, and lower-limb amputation are down by more than 50% over the last two decades. Now the bad news: during the same time period, the number of people with diabetes has soared, according to a report in the Annals of Internal Medicine. Today, about 21 million American adults are living with diabetes, and that number is on the upswing. Nearly 70% of Americans are overweight or obese. Unless something is done to reverse this trend, millions more Americans could edge closer to diabetes. Dr. Osama Hamdy, medical director of the Obesity Clinical Program at Harvard-affiliated Joslin Diabetes Center and author of The Diabetes Breakthrough, a newly published book from Harvard Health Publishing, offers some strategies for preventing diabetes.