Not necessarily. Sometimes changing your diet, losing weight and increasing your activity level can control type 2. "Since overeating and a sedentary lifestyle can increase the risk of diabetes, interventions that reduce or improve these factors can almost always improve blood sugar levels," says David M. Nathan, M.D., director of the Diabetes Center at Massachusetts General Hospital in Boston. The beneficial effects can be seen within days or weeks. However, long-term weight loss is difficult for many to maintain, so the majority of patients do require medications, says Dr. Nathan. The first line of defense is typically metformin, which quickly lowers blood glucose with few side effects. It also reduces high LDL (bad) cholesterol and may aid in weight loss. If you can't reach your target glycemic levels with metformin, most doctors suggest trying additional medications. The last resort is often insulin therapy.