Vitamin C might help you lose a few, and it might help you keep those few off too.

Research shows that the human body needs sufficient vitamin C to burn fat, the key to keeping excess weight from stacking up. Nothing too difficult about what to do with this news: Pop your C supplement or chew on some vitamin C-rich foods before your next fitness feat. Even better, snack on it throughout the day if you can. Try some grapefruit in the morning, have an orange for lunch, and fill your dinner plate with treats like red bell peppers, broccoli, and brussels sprouts.

Some background: Vitamin C study participants with low concentrations of C in their blood walked on a treadmill for one hour and burned 25% less fat than people with adequate C in their blood. It didn't take much to bring fat-burning levels up, though. A dose of C is all it takes to create carnitine, a substance that turns fat into fuel.

How much C do you need? Click here to find out.