Weekly challenge: think diet and exercise, not pills, to shed those extra 10 pounds

By Deborah Kotz, Globe Staff

Last week, the US Food and Drug Administration approved lorcaserin (Belviq) to fight obesity, and another fat-fighting drug may be approved later this month, but that doesn’t mean you can rest easy, pop a pill, and forgo efforts to improve your diet and activity levels.

“These drugs won’t work without behavioral interventions,” said Dr. Caroline Apovian, director of the nutrition and weight management center at Boston Medical Center. Lorcaserin, in particular, produced only modest weight loss -- about 5 percent on average -- in those who took the drug during clinical trials. That’s because some of the initial weight loss was reversed in study participants who took the drug beyond a year.

What’s more, lorcaserin and other drugs to treat obesity are meant for, well, only those who are truly obese -- which means they have at least 30 or more pounds to lose, not 10 or 20. No one knows how well prescription drugs work if you just want to shed an extra 10 or 20 pounds because the drugs haven’t been tested in those who aren’t obese.

The American Council on Exercise recommends that those who are obese consider prescription drugs to be “a supplement to -- rather than a replacement for -- diet and exercise”. Given that these drugs have possible side effects such as heart risks, the rest of us would be better off reducing portion sizes, eating a low glycemic index diet, and taking more steps throughout the day.