Adequate water intake is essential for all your body’s functions, and the more you drink, the better your chances of staying thin. In one University of Utah study, dieting participants who were instructed to drink two cups of water before each meal lost 30 percent more weight than their thirsty peers. And you can magnify the effect by adding ice. German researchers found that six cups of cold water a day could prompt a metabolic boost that incinerates 50 daily calories. That’s enough to shed five pounds a year!

BEVERAGE BONUS: Drinking water is always a smart idea, but there are some beverages that should be avoided at all costs. Protect yourself—and your waistline—from the 20 Worst Drinks in America.