The Diabetes Prevention Program (DPP) ended a year early because the findings clearly answered the question of whether type 2 diabetes can be delayed or prevented through diet and exercise or medication. The results were published in February 2002 in the New England Journal of Medicine. Among the findings:

• Members of the first group, who received intensive counseling on making lifestyle changes, reduced their risk of developing type 2 diabetes by 58 percent. Participants who were age 60 and older reduced their risk by 71 percent. About 4.8 percent of the group developed diabetes each year during the study. On average, the participants achieved their weight goal, an average loss of 7 percent (15 pounds), in the first year of the study and maintained a 5 percent total loss for the duration of the study.
  
  
• People in the second group, who took the drug metformin, reduced their risk of developing type 2 diabetes by 31 percent. This treatment was most effective in participants age 25 to 44 and in obese people with a body mass index of 35 or higher. About 7.8 percent of the group developed diabetes each year during the study.

A follow-up study released in 2006 indicated that participants taking metformin were 38 percent less likely than those taking a placebo to become diabetic.

• In the third group, who took the placebos (pills that have no effect), 11 percent of the participants developed diabetes each year during the study.

The DPP showed that moderate weight loss and regular exercise can prevent or delay the onset of type 2 diabetes. It also showed metformin to be effective in delaying the onset of the disease, although the reduction was significantly less.

The findings are considered significant because they offer the millions of people at high risk of developing diabetes a way to significantly reduce their risk – a moderate weight loss of 5 to 7 percent body weight (10 to 15 pounds), achieved through healthier eating habits and 30 minutes of exercise five days a week.

Weight loss and exercise reduce a person’s risk of diabetes by improving the body’s ability to use insulin and manage glucose (blood sugar). They also reduce the risk of heart conditions, stroke, some forms of cancer and many other health problems.