By Liz Ward, Men's Health:
Slashing too many calories, particularly protein calories, pushes the body to conserve calories rather than burn them. It also forces your body to break down muscle tissue to fuel its vital operations. But that muscle is the key to your metabolism, or the speed at which you burn calories. More muscle means a faster metabolism and less body fat.
Solution: You do need to cut calories to lose weight. (Cut 500 today by eliminating one can of beer, 30 chips, and one Oreo from your diet.) But you need to make sure you're eating at least 1,600 to 1,800 calories each day to keep your metabolism from shutting down. And never cut protein during a diet. If you're a sedentary 200-pounder, you need about 75 grams of protein (about two chicken breasts) a day for muscle preservation. If you're lifting weights, aim for twice that much. Doing aerobics? Pick a number in between.
