7. Hit Your Target Weight
You don't have to eat like a calorie-restricted rat, but it pays to establish limits and maintain a healthy body weight. Excess weight is a tremendous risk factor for chronic conditions such as cancer, diabetes, heart disease, and arthritis, says Clark.
Calculate your best weight this way, she adds: Women optimally weigh 100 pounds at 5 feet, and 5 pounds more for each additional inch; men weigh 106 pounds at 5 feet, plus 6 pounds for each additional inch. If you are sedentary, you need to eat only 14 calories per pound of your body weight to maintain it; if very active, you need 16 calories per pound. Cut 500 calories per day to lose about a pound a week.