20 Fittest Foods

14) Milk
118 calories per cup
Get 3 servings of dairy per day
You know milk does a body good, but you may not know that skipping dairy makes your body angry, sort of. When you're not getting enough, your body releases hormones that cause your cells to retain calcium-and fat, says Michael Zemel, Ph.D., director of The Nutrition Institute at the University of Tennessee. Calories still count, so you should drink your milk by the glass rather than the gallon. But just make sure you get some. "There are components in dairy that help turn on your body's fat-burning system and slow down the storage of fat," says Zemel. And although other forms of supplements are great, this is one case in which the real thing works the best.

13) Water
0 calories
Drink Eight 8-oz glasses per day
You know you need to be drinking more water, and for good reason. Water flushes toxins from your system, regulates body temp, acts as an insulator for joints, prevents kidney stones, and supplies the body with a raft of crucial minerals, says Marietta Amatangelo, R.D., of Germantown, Md. "Without water, none of the other super-foods would matter."

Although water helps in every way, it may be at its most powerful when it comes to weight loss. Drinking a glass or two of water a half hour or so before mealtime, for example, can help take the edge off your hunger.

Getting in all that water each day seem like a drag? Try making a half gallon of sugar-free lemonade you can sip throughout the day, or buy a pack of calorie-free flavorings to add to your water bottle at work.