A person's caloric requirement depends on his body size and exercise level. Sedentary people of both genders will keep their weight stable by taking in about 13 calories per pound of body weight each day. Moderate physical activity boosts this requirement to 16 calories a pound, and vigorous exercise calls for about 18 calories a pound. On average, a moderately active 125-pound woman needs 2,000 calories a day; a 175-pound guy with a similar exercise pattern needs 2,800 calories. And like women, men will lose weight only if they burn more calories than they take in.

Dairy. Women should get 3 cups of dairy each day, but most women get only half that amount.6 If you can’t drink milk, try to eat low-fat plain yogurt or low-fat cheese. Dairy products are among the best food sources of the mineral calcium, but some vegetables such as kale and broccoli also have calcium, as do some fortified foods such as fortified soymilk, fortified cereals, and many fruit juices. Most girls ages 9 to 18 and women older than 50 need more calcium for good bone health.