If you do decide to diet, you still need to maintain good nutrition. You want to cut back on calories, not nutrients. And while you want to reduce fat, don't eliminate it entirely. Some studies suggest that older women who maintain a higher body-fat percentage are less likely to suffer from osteoporosis and other conditions associated with menopause. Fat cells also retain estrogen, which helps maintain the calcium in your bones. Younger women should be careful, too: a low body fat percentage can lead to infertility; below 17 percent may lead to missed periods, also known as amenorrhea.
Here, too, body size is the main difference between the needs of males and females. Despite all the hype about high-protein diets, our protein requirements are really quite modest — only about a third of a gram per pound of body weight. For a 125-pound woman, that amounts to about 42 grams, for a 175-pound man, 58 grams. That's a tiny difference, just about half an ounce a day.
Getting enough water also is important. Many experts recommend at least eight 8-ounce glasses of water daily—more if you exercise frequently or are exposed to extremes of heat and cold. The 2010 Dietary Guidelines for Americans emphasize drinking more water and other calorie-free beverages, along with fat-free or low-fat milk and 100 percent fruit juices, instead of calorie-packed regular sodas.
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.