Young adults. Teen girls and young women usually need more calories than when they were younger, to support their growing and developing bodies. After about age 25, a woman’s resting metabolism (the number of calories her body needs to sustain itself at rest) goes down. To maintain a healthy weight after age 25, women need to gradually reduce their calories and increase their physical activity.
What's a man to do? Fortunately, he does not have to choose between his bones and his prostate. The solution is moderation. The Baltimore Longitudinal Study of Aging, for example, found no link between a moderate consumption of calcium (about 800 mg a day, two-thirds of the RDA) and prostate cancer. In addition, a randomized clinical trial of calcium supplements of 1,200 mg a day found no effect on the prostate, but only 327 men were in the calcium group, and the supplementation lasted just four years. Finally, the Harvard scientists speculate that a high consumption of vitamin D may offset the possible risks of calcium, so a daily multivitamin may also help.
Consult your health care professional. Women of childbearing age may want to consider taking folic acid supplements to reduce the risk of having a pregnancy affected with neural tube defects. Many women and teenage girls don't get enough calcium or vitamin D, both of which are critical to healthy bones and avoiding osteoporosis. Some people with diabetes appear to benefit from chromium. Vegetarians, especially vegans, may want to consider supplements to obtain nutrients they aren't getting from animal products.
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.
What you eat and drink is influenced by where you live, the types of foods available in your community and in your budget, your culture and background, and your personal preferences. Often, healthy eating is affected by things that are not directly under your control, like how close the grocery store is to your house or job. Focusing on the choices you can control will help you make small changes in your daily life to eat healthier.
It's a cliché, to be sure, but a balanced diet is the key to good nutrition and good health. Following that diet, however, isn't always that easy. One challenge is that women often feel too busy to eat healthfully, and it's often easier to pick up fast food than to prepare a healthy meal at home. But fast food is usually high in fat and calories and low in other nutrients, which can seriously affect your health. At the other extreme, a multimillion dollar industry is focused on telling women that being fit means being thin and that dieting is part of good nutrition.
You know it's easier to fall off the healthy-eating wagon when the person across the table from you is going whole-hog on mozzarella sticks, but science still felt the need to study this. And evidence presented at the 2013 Agricultural and Applied Economic Associations annual meeting backs you up: In the study, people made similar dining choices as their companions did, possibly because we simply want to fit in. Not all eating partners make a bad influence, though. The report further speculates that if you're eating with a health-conscious person, you may be more likely to order something more nutritious as well.
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.
Choline: Some studies link low choline levels to increased risk of neural tube defects. Recommended levels have been established for this nutrient, but it's easy to get enough in your diet. Eggs are an excellent source of choline, for example. “Eating a few eggs a week should give you all you need,” Frechman says. “Most people can eat the equivalent of an egg a day without worrying about cholesterol.” Other choline-rich food sources include milks, liver, and peanuts.
Omega-3s: These essential fatty acids, EPA and DHA, play many roles in the body, including building healthy brain and nerve cells. Some studies show that omega-3s, especially DHA, can help prevent preterm births. Even women who don't plan to have children should be sure to get plenty of omega-3s. These healthy oils have been shown to reduce the risk of heart disease, the number one killer of women.
A healthy vegetarian diet falls within the guidelines offered by the USDA. However, meat, fish and poultry are major sources of iron, zinc and B vitamins, so pay special attention to these nutrients. Vegans (those who eat only plant-based food) may want to consider vitamin and mineral supplements; make sure you consume sufficient quantities of protein, vitamin B12, vitamin D and calcium. You can obtain what you need from non-animal sources. For instance:
There's not much doubt about this one: Women need more iron than men, because they lose iron with each menstrual period. After menopause, of course, the gap closes. The RDA of iron for premenopausal women is 18 mg a day, for men 8 mg. Men should avoid excess iron. In the presence of an abnormal gene, it can lead to harmful deposits in various organs (hemochromatosis). Since red meat is the richest dietary source of iron, it's just as well that men don't need to wolf down lots of saturated fat to get a lot of iron.
Even if you are the most independent exerciser around, give a group fitness class a shot at least once a week—you may find that you enjoy it more than sweating solo. “Happiness and health are shared through social connectedness and closeness,” says Greg Chertok, director of sport psychology at the Physical Medicine and Rehabilitation Center in New Jersey. “Geography and proximity are predictors of how contagious emotions can be, and this may translate into an athletic environment too.” Sign up for Bikram, CrossFit, spin, or Zumba, and you could find yourself—gasp!—smiling at the gym thanks to your classmates.
The recommended daily intake for vitamin E is 15 mg. Don't take more than 1,000 mg of alpha-tocopherol per day. This amount is equivalent to approximately 1,500 IU of "d-alpha-tocopherol," sometimes labeled as "natural source" vitamin E, or 1,100 IU of "dl-alpha-tocopherol," a synthetic form of vitamin E. Consuming more than this could increase your risk of bleeding because vitamin E can act as an anticoagulant (blood thinner).