Belviq, a weight-loss drug from Arena Pharmaceuticals, was approved by the Food and Drug Administration in 2012. With the agency's approval of Saxenda in December, there are four new weight-loss pills available. Arena Pharmaceuticals Inc/Reuters/Landov hide caption

itoggle caption Arena Pharmaceuticals Inc/Reuters/Landov

Even versions of Zi Xiu Tang Bee Pollen labeled "genuine" and "anti-counterfeit" have been found to contain the drug sibutramine, which was supposed to come off the U.S. market in 2010 for safety reasons. Food and Drug Administration hide caption

itoggle caption Food and Drug Administration

Photos from Liz Paul's blog entries on Prior Fat Girl. The blog chronicles women's weight loss journeys. Courtesy of Liz Paul/PriorFatGirl.com hide caption

itoggle caption Courtesy of Liz Paul/PriorFatGirl.com

Carlos Romero and girlfriend Kate Rowe sit down for a meal they cooked together. Two years ago, Carlos Romero weighed 437 pounds. Mike Kane for NPR hide caption

itoggle caption Mike Kane for NPR

Researchers say that setting your thermostat a little lower can help you burn more calories. iStockphoto hide caption

itoggle caption iStockphoto

People following a 5-2 diet would eat lean protein and non-starchy vegetables two days a week. Heather Rousseau/NPR hide caption

itoggle caption Heather Rousseau/NPR

A player avatar runs on a treadmill in the virtual world of Second Life. Researchers used the online game to see if it could help people maintain weight loss habits in the real world. Courtesy of Univeristy of Kansas Medical Center hide caption

itoggle caption Courtesy of Univeristy of Kansas Medical Center

Drinking diet soda and other low-calorie drinks may help you manage weight, but experts say plain old H2O is still the best way to go. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Eating low-glycemic foods, or foods that take longer to digest, may help you feel fuller for a longer period of time. Robyn Mackenzie/iStockphoto.com hide caption

itoggle caption Robyn Mackenzie/iStockphoto.com

It doesn't take a transcontinental flight to end up out of sync with your body clock. It might just be that you stay up too late. iStockphoto.com hide caption

itoggle caption iStockphoto.com