You need to cut calories to lose weight, but it’s important not to overdo it. Going too low delivers a double whammy to your metabolism. When you eat less than you need for basic biological function (about 1,200 calories for most women), your body throws the brakes on your metabolism. It also begins to break down precious, calorie-burning muscle tissue for energy, says Benardot. “Eat just enough so you’re not hungry—a healthy snack midmorning and midafternoon between three meals (about 430 calories each) will keep your metabolism humming.” By eating a meal every 3 to 4 hours, you’ll stay satisfied and keep from overeating later in the day.