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.
The new guidelines encourage eating more nutrient-dense food and beverages. Many of us consume too many calories from solid fats, added sugar and refined grains. The guidelines promote a diet that emphasizes vegetables, fruits, whole grains, fat-free or low-fat dairy products, seafood, lean meat and poultry, eggs, beans and peas, and nuts and seeds.
Iron: Essential for healthy blood cells, iron becomes especially important when girls begin to menstruate. With each period, a woman loses small amounts of iron. “About 10% of American women are iron deficient,” says Dorothy Klimis-Zacas, PhD, a professor of nutrition at the University of Maine and co-editor of Nutritional Concerns of Women (CRC Press, 2003). “About 5% have iron deficiency anemia.” Symptoms of low iron include fatigue, impaired immunity, and poor performance at school or work.
Nutrition is particularly important when you are pregnant. Weight gain during pregnancy is normal—and it's not just because of the growing fetus; your body is storing fat for lactation. The National Academy of Sciences/Institute of Medicine (NAS/IOM) has determined that a gain of 25 to 35 pounds is desirable. However, underweight women should gain about 28 to 40 pounds, and overweight women should gain at least 15 pounds. The IOM has not given a recommendation for an upper limit for obese women, but some experts cap it as low as 13 pounds. If you fit into this category, discuss how much weight you should gain with your health care professional. Remember that pregnancy isn't the time to diet. Caloric restriction during pregnancy has been associated with reduced birth weight, which can be dangerous to the baby.
Having the proper footwear is essential for any workout, and for winter runs, that means sneaks with EVA (ethylene vinyl acetate), says Polly de Mille, an exercise physiologist who oversees New York Road Runner's Learning Series for first-time New York City Marathon runners. “Polyurethane tends to get really stiff and cold in the winter, which could increase your risk of injury.” Another important feature is a waterproof and windproof upper: Look for shoes made with Gortex, or wrap your mesh uppers in duct tape to keep feet dry and warm.
Use MyPlate (PDF – 281 KB) as a guide to build a healthy diet. Think about filling your plate with foods from the five food groups — fruits, vegetables, grains, proteins, and dairy — at each meal. Snacks can be a good way to fill in fruits and whole grains you might have missed at meals. Most of us don’t need complicated calorie counting programs or special recipes for healthy eating.
Good sources of iron include liver, kidneys, red meat, poultry, eggs, peas, legumes, dried fruits and dark, green leafy vegetables. Three ounces of cooked chicken liver contains 7.2 mg of iron; a cup of cooked spinach contains 6.4 mg. Your health care professional will probably recommend iron supplements during pregnancy (probably starting at 30 mg per day).
The total fat in your daily diet should average no more than 30 percent of your total calories consumed. And saturated fat should be no more than 10 percent of those 30 percent of calories. The amount of fat and saturated fat you eat depends on the foods you select and consume that have fat in them. Consider consulting with a nutrition professional to learn more about how to calculate your fat needs and to not exceed what are healthy amounts. There are many tools available to help you determine how much fat you should consume each day based on your current energy and nutrition needs. Reading food labels is one way to begin to identify where and how much fat is in particular food items.
Always be sure you get regular servings of dairy products, calcium-rich tofu and greens, and calcium-fortified orange juice. Also, eat lean meat and/or high-quality protein combinations such as pinto beans and rice. Avoid fiber supplements as these bind calcium and other minerals in the intestinal tract. When this happens the absorption of essential nutrients decreases.