The average woman should get 10 to 35 percent of her daily calories from protein. Protein helps prevent muscle tissue from breaking down and repairs body tissues. Sources of animal proteins include meat, fish, poultry, eggs, milk and cheese. Vegetable proteins include dried beans and peas, peanut butter, nuts, bread and cereal. (A three-ounce serving of cooked chicken contains about 21 grams of protein.)
Katz DL, O'Connell M, Yeh MC, Nawaz H, Njike V, Anderson LM, Cory S, Dietz W; Task Force on Community Preventive Services. Public health strategies for preventing and controlling overweight and obesity in school and worksite settings: a report on recommendations of the Task Force on Community Preventive Services. MMWR Recomm Rep  2005;54(RR-10):1–12.
In addition to diet, exercise and other lifestyle factors can also play an important role in bone health. Smoking and drinking too much alcohol can increase your chances of developing osteoporosis, while weight-bearing exercise (such as walking, dancing, yoga, or lifting weights) can lower your risk. Strength or resistance training—using machines, free weights, elastic bands, or your own body weight—can be especially effective in helping to prevent loss of bone mass as you age.