Eating a small piece of chocolatecan give you a quick, natural energy boost, says Teitelbaum. Chocolate contains a modest amount of caffeine, along with theobromine, caffeine's gentler cousin. Plus, in moderation, it isn't as bad for you as you think. "People don't realize that chocolate is a health food," he says. "It's full of phenols and other antioxidants that keep the heart and brain healthy."

The darker the chocolate, the more nutrients, caffeine, and theobromine you'll get. But Teitelbaum says even breaking off a few squares of a milk-chocolate Hershey's bar can do the trick. Just don't eat more than 1 ounce a day—that's a little more than half of your average bar—because chocolate still has a lot of sugar and fat.