A new study shows that a program of diet, exercise and behavioral therapy when used in combination with the weight loss drug Meridia® resulted in significantly greater weight loss among obese adults than treatment with the medication alone, according to University of Pennsylvania researchers..

The one-year study, reported in the November 17, 2005 issue of The New England Journal of Medicine and was supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), involved a total of 224 obese adults aged 18 to 65 years.

Participants were randomly assigned to one of four groups: 1. weight loss medication alone; 2. lifestyle modification alone; 3. weight loss medication plus lifestyle modification; and 4. weight-loss medication plus brief physician-mediated therapy. All groups were prescribed a 1200 to 1500 calorie diet and the same exercise plan.

After one year, patients in the weight-loss medication plus lifestyle modification group lost an average of more than 26 pounds — more than double the weight loss seen with medication alone (11 pounds).

In addition, 73 percent of participants in the weight-loss medication plus lifestyle modification group lost 5 percent or more of their initial body weight, compared to 42 percent of participants in the weight-loss medication alone group.

“The take home message is that weight loss medications will be most effective when they are combined with a reduced calorie diet and increased physical activity,” says Thomas A. Wadden, Ph.D., Professor of Psychology in the Department of Psychiatry at the University of Pennsylvania School of Medicine, and lead author of the study. “Weight loss medication used alone can produce some weight loss, but lifestyle modification treatment can help patients acquire skills to successfully make changes in their diet and physical activity.”

Other sources: National Institute of Diabetes and Digestive and Kidney Diseases