The talk: It speeds your metabolism

The truth: "This is an urban legend," says Liz Applegate,

Ph.D., director of sports nutrition at the University of California in Davis. "There is no valid research proving it."

Another, albeit contradictory, myth: Coconut water makes you fat. This bad rap came from coconut milk, which is made from pressed coconut meat and packs 445 calories per cup, most from saturated fat. The water (the fluid in young coconuts) has only 46 calories per cup. Of course, for a truly trimming sip, opt for zero-calorie water, coffee or tea.