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.