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.
Actually, more people suffer from food intolerances, which don't involve the immune system. However, food intolerance symptoms—such as intestinal distress—may mimic those of a food allergy. If you have a food intolerance, talk to a nutritionist about diagnosis and treatment; if you have food allergies, you need to see an allergist. Whether you have food allergies or intolerance, you will need to develop a diet that fits your needs and avoids foods that trigger a reaction.
You should consume only 25 percent to 35 percent of your total calories per day from fat, with a significant portion from good fats like omega-3 and omega-6 fatty acids. According to the American Heart Association, women should get at least five to 10 percent of their total daily calories from omega-6 fatty acids (equal to 12 to 20 grams), and anywhere from 0.5 to 3 grams of omega-3 fatty acids, depending on individual risk for heart disease.
Iron: Iron, too, remains a critical nutrient. Adult women between the ages of 19 and 50 need 18 mg a day. Pregnant women should shoot for 27 mg a day. “The volume of blood almost doubles when women are pregnant, which dramatically increases the demand for iron,” Schwartz tells WebMD. After delivery, lactating women need far less iron, only about 9 mg, because they are no longer menstruating. But as soon as women stop breast-feeding, they should return to 18 mg a day.
If you count calories, count fat calories, too. Food labels indicate how many calories come from fat, both in actual grams and in percentages. This helps you assess the percentage of fat in your diet. If the total number of fat calories is 30 percent or more of the total calories you consume in a day, you probably need to cut back. But don't be misled by terms like "lower fat." Ask yourself "lower than what?" and look at the overall percentage of fat calories in the food.
During adolescence and early adulthood, women need to consume foods rich in calcium to build peak (maximum) bone mass. This will reduce the risk of developing osteoporosis, a progressive condition where there is a loss of bone that leaves those affected more susceptible to fractures. Women also need an adequate iron intake because they lose iron through menstruation. Women also need an adequate intake of calories to support energy and nutritional needs in order for the body to function properly. The amount of calories that an individual needs varies for each person and is based on age, gender and activity level. As a general recommendation, women between 23 and 50 years of age generally need between 1,700 and 2,200 calories per day to maintain their current energy needs and body weight. Older women generally require fewer calories to support and sustain energy needs. Consuming fewer than 1,500 calories per day, even in attempts to lose weight, can put women at nutritional risk and can result in malnutrition and poor health. For more information on how to calculate one’s nutritional needs, go to www.choosemyplate.gov and insert your personal information. The 2005 Dietary Guidelines for Americans is another reference or guide to assist you in learning to eat a balanced and nutritious diet for good health.
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.
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.
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.
According to the American Heart Association, it's better to eat more complex carbohydrates (vegetables, fruits and whole grains) than simple carbohydrates found in sugars. Complex carbohydrates add more fiber, vitamins and minerals to the diet than foods high in refined sugars and flour. Foods high in complex carbohydrates are usually low in calories, saturated fat and cholesterol.
Adopting a plant-based diet could help tip the scales in your favor. A five-year study of 71,751 adults published in the Journal of the Academy of Nutrition and Dietetics found that vegetarians tend to be slimmer than meat-eaters even though both groups eat about the same number of calories daily. Researchers say it may be because carnivores consume more fatty acids and fewer weight-loss promoting nutrients, like fiber, than herbivores do. Go green to find out if it works for you.