Medicine May Help With Weight Loss

Norris S, Zhang X, Avenell A, et al.: Efficacy of pharmacotherapy for weight loss in adults with type 2 diabetes mellitus. Arch Intern Med 164:1395–1404, 2004.

What is the problem and what is known about it so far?

Obesity is a growing problem in the U.S. Obese people are at a higher risk of getting health problems like heart disease and type 2 diabetes. Therefore, it is important to maintain a healthy weight and to encourage obese people to lose weight. However, losing weight is challenging for many. There are medications that may be able to help, but doctors still don't understand how well they work.

The researchers wanted to know how effective certain medications were in helping people with type 2 diabetes lose weight.

Who was studied?

The researchers reviewed 14 studies, conducted by other scientists, which evaluated three medicines for weight loss: fluoxetine, orlistat, and sibutramine. There were 2,231 participants.

How was the study done?

The participants were studied for 57 weeks to see how much weight they lost. Most of the studies counseled participants on diet and exercise. In each study, the effects of active drugs were compared to treatment with a placebo (a “fake” pill). Researchers analyzed trends in weight loss in all studies, and studied levels of A1C, a measure of long-term glucose control.

What did the researchers find?

The participants lost weight on all three medications over a 26- to 52-week period. But they didn't lose much weight, ranging from 6 to 10 pounds or about 2% to 3% of their starting weight. Those taking weight loss medications also lowered their long-term glucose levels to a healthy range. There were no serious side effects from the medications. The long-term health benefits and safety of these drugs are unclear.

What were the limitations of the study?

All 14 of the studies in this project were slightly different, so the results may not be comparable. Some studies were sponsored by companies that make weight loss drugs, which could create a conflict of interest. Lifestyle factors that may affect weight and health risks also were not studied.

What are the implications of the study?

In some cases, treating obesity with medication, diet, and exercise may help people to lose weight. However, more research is needed to understand the long-term effects of using weight loss medications.