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

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The FDA hasn't approved a new weight-loss drug since 1999. In the meantime, Americans' waistlines have continued to grow. M. Spencer Green/AP hide caption

itoggle caption M. Spencer Green/AP

Jenny Craig brand ambassador and singer Mariah Carey (left) poses with Dana Fiser, CEO of Jenny Craig, at a press conference in New York City in November. Cindy Ord/Getty Images hide caption

itoggle caption Cindy Ord/Getty Images