Ducking diabetes. (Quick Studies).

Weight loss and exercise prevent diabetes more effectively than drugs, says a new study of more than 3,000 overweight middle-aged people who had higher-than-normal blood sugar (but not diabetes).

Each got either a placebo, Glucophage (a drug used to treat high blood sugar), or 16 one-on-one sessions to help them lose weight and exercise. After nearly three years, 29 percent of the people in the placebo group had developed diabetes, compared with 22 percent of the Glucophage-takers and just 14 percent of those in the exercise-and-weight-loss group.

The exercisers didn't need to run marathons. Roughly 58 percent of them met the exercise goal (at least 2 1/2 hours a week of moderate aerobic activity like brisk walking). And 38 percent met the weight-loss goal (they dropped at least seven percent of their body weight by eating a healthy low-calorie; low-fat diet).

What to do: Get off the couch, office chair, or driver's seat for at least 20 to 30 minutes of walking or other activity every day. And cut calories with a healthy diet that includes lots of fruits and vegetables.

New England Journal of Medicine 346: 393, 2002.