Healthy eating is a way of eating that improves your health and helps prevent disease. It means choosing different types of healthy food from all of the food groups (fruits, vegetables, grains, dairy, and proteins), most of the time, in the correct amounts for you. Healthy eating also means not eating a lot of foods with added sugar, sodium (salt), and saturated and trans fats.
Not everyone who is underweight suffers from an eating disorder, but anorexia and bulimia are serious health problems in this country; an estimated 500,000 women suffer from anorexia, and 1 to 2 million women struggle with bulimia. Women with anorexia nervosa starve themselves and/or exercise excessively, losing anywhere from 15 percent to 60 percent of their normal body weight. Some die. Women with bulimia nervosa binge on large quantities of food—up to 20,000 calories at one time—and then try to get rid of the excess calories. Some purge by inducing vomiting, abusing laxatives and diuretics or by taking enemas. Others fast or exercise to extremes.
From misconceptions like equating healthy eating with bland food and unrealistic fitness goals (think v-cut abs and thigh gap) to contradictory food studies and unsustainable fad diets, there are numerous factors that make healthy eating seem like a complicated affair. But it doesn't have to be so overwhelming. “Healthy eating should be varied and delicious,” says Fiorella DiCarlo, an NYC-based registered dietitian. “ The more stimulated your palate is, the more likely you are to adhere to eating nutritious food .”
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.
Processing of food reduces its nutritional content, and the finished products are often based on fractions of the original foods. One example is milling grain to make white flour,  which has a lower nutritional density than whole grain flour. The reduction in nutritional value has accelerated since whole foods are now divided into pieces, for example, boneless chicken breast. When meat is injected with saline to increase the volume, the relative level of essential nutrients is reduced. In the United States, many supermarkets in low-income rural and inner city areas have a limited selection of nutrient-dense foods, compared with high-income areas. 
As women, many of us are prone to neglecting our own dietary needs. You may feel you’re too busy to eat right, used to putting the needs of your family first, or trying to adhere to an extreme diet that leaves you short on vital nutrients and feeling cranky, hungry, and low on energy. Women’s specific needs are often neglected by dietary research, too. Studies tend to rely on male subjects whose hormone levels are more stable and predictable, thus sometimes making the results irrelevant or even misleading to women’s needs. All this can add up to serious shortfalls in your daily nutrition.
Nutritional supplements are used for many purposes. They can be added to the diet to boost overall health and energy; to provide immune system support and reduce the risks of illness and age-related conditions; to improve performance in athletic and mental activities; and to support the healing process during illness and disease. However, most of these products are treated as food and not regulated as drugs are.
Watch your portion sizes: Check to see what the recommended portion sizes of foods you eat looks like in the bowls, plates, and glasses you use at home. When dining out avoid "supersizing" your meal or buying "combo" meal deals that often include large-size menu items. Choose small-size items instead or ask for a take home bag and wrap up half of your meal to take home before you even start to eat.
Folate is most important for women of childbearing age. If you plan to have children some day, think of folate now. Folate is a B vitamin needed both before and during pregnancy and can help reduce risk of certain serious common neural tube birth defects (which affect the brain and spinal chord). Women ages 15-45 should include folate in their diet to reduce the risk for birth defects if one becomes pregnant, even if one is not planning a pregnancy.
Sugar is a source of calories, not nutrients. Consuming too much sugar can lead to weight gain and tooth decay. Contrary to what many people think, there is no evidence linking high-sugar diets to hyperactivity or diabetes. However, high-fructose corn syrup, found in most processed foods, is linked with obesity, and obesity increases your risk for developing diabetes and other conditions.
Carbohydrates should provide 45%–65% of your daily calories. Most of those calories should come from the complex carbohydrates in high-fiber and unrefined foods, such as bran cereal and other whole-grain products, brown rice, beans and other legumes, and many fruits and vegetables. These carbohydrates are digested and absorbed slowly, so they raise the blood sugar gradually and don't trigger a large release of insulin. People who eat lots of these foods have higher HDL ("good") cholesterol levels and a lower risk of obesity, diabetes, and heart disease. A good amount of soluble fiber in the diet lowers LDL ("bad") cholesterol, and high-fiber diets reduce the risk of intestinal disorders ranging from constipation and diverticulosis to hemorrhoids. Some studies have shown that fiber may help reduce the risk of colon cancer. Men need more fiber than women: 38 vs. 25 grams a day before the age of 50 and 30 vs. 21 grams a day thereafter.