Women and Nutrition : Fat, Fiber

by Food and Drug Administration (FDA)

(Page 2 of 2)

Fat

In the United States, out of every 100,000 women, approximately 27 die from breast cancer each year. In Japan, breast cancer deaths are fewer than 7 per 100,000. Some scientists think that the difference in death rates may be related to the different amounts of fat in the average diet in each country — 40 percent for American women versus 20 percent in Japan.

"We believe pretty strongly in the link [between high-fat diets and breast cancer]," says Jeffrey McKenna, director of NCI's Cancer Awareness Program.

Population studies have also linked high-fat diets to other cancers, particularly colorectal cancer.

Fat does, however, serve a purpose in the diet. Fats in foods provide energy and help the body absorb certain vitamins. But it is as easy as pie (and doughnuts, ice cream, and sirloin steaks) to eat too much.

For a healthy diet, the diet and health report of the National Research Council recommends reducing fat to no more than 30 percent of total calories. (Figure out your fat intake.) But that's not all. In terms of heart disease, the kinds of fat you eat are as important as how much.

There are three kinds of fat — saturated, polyunsaturated and monounsaturated. All three are equal when it comes to calories — 9 per gram (compared to 4 calories per gram for protein or carbohydrate). But they aren't equal when it comes to how they affect your health.

More than anything else in the diet, saturated fat can raise your blood cholesterol level. Because of this risk, less than one-third of your daily fat intake (less than 10 percent of total calories) should come from saturated fats.

That's the bad news. The good news is polyunsaturated and monounsaturated may actually lower blood cholesterol levels. The diet and health report recommends that not more than 10 percent of total calories should be from polyunsaturated fat, and monounsaturated fat should make up the remaining 10 percent.

The foods with the highest amounts of saturated fat come from animals — meat, of course, and foods derived from animals, such as butter, cream, ice cream, and cheese. In addition to animal products, coconut and palm kernel oils are very high in saturated fat — over 90 percent.

The best sources for polyunsaturated fats are plant-based oils — sunflower, corn, soybean, cottonseed, and safflower. Monounsaturated fats are found in the largest amounts in olive, canola and peanut oils.

Fiber

An apple a day — that is, a whole apple with the skin — will give you approximately 3.6 grams of fiber. That's a good start, but you still need a lot more fruits, vegetables, and whole grains to meet the daily level of 20 to 30 grams of fiber recommended by the National Cancer Institute.

Eating foods with plenty of complex carbohydrates and fiber (vegetables, fruits, and grain products) is part of a healthy diet for several reasons. A fiber-rich diet is helpful in the management of constipation and may be related to lower rates of colon cancer. These types of foods are generally low in fat and can be substitutes for fatty foods.

Fiber comes in two forms — insoluble and soluble. Insoluble fiber, mostly found in whole-grain products, vegetables and fruit, provides bulk for stool formation and helps move wastes more quickly through the colon. Another benefit is the full feeling fiber may create in the stomach, a possible deterrent to overeating.

Soluble fiber has been linked to lowering blood cholesterol levels, but that's still a research area according to the Surgeon General's Report on Nutrition and Health. There are many sources of soluble fiber, including peas and beans, many vegetables and fruits, and rice, corn and oat bran. There are even small amounts in pasta, crackers, and other bakery products.

Although foods containing fiber seem to exert a protective effect against some cancers, the diet and health report points out there is no conclusive evidence that dietary fiber itself, rather than other components, exerts this effect. Therefore, the report does not recommend the use of fiber supplements.

As important as fiber is to good health, it can be overdone. NCI recommends an upper limit of 35 grams a day. More probably won't further increase the benefits from fiber, and may interfere with the body's ability to absorb iron and other minerals.

When increasing the amount of fiber in your diet, do it slowly, so your body can become accustomed to handling it. Adding too much fiber too quickly may lead to uncomfortable side effects, including abdominal discomfort, flatulence and diarrhea.

Food Preparation

Carefully selecting foods for a well-balanced diet can end up a wasted effort if equal care isn't used in the kitchen. Some important points to help make the most of healthy food: To help reduce fat, broil, bake or microwave food rather than frying or deep-fat frying. Cook vegetables in as little water as possible, or, instead of boiling food, try steaming. The steamer basket keeps the food above the water so the nutrients can't be washed away. Also, heat can destroy some nutrients, so don't overcook. Use fresh foods as soon as possible to avoid loss of vitamins. Season vegetables with herbs and spices instead of high-fat sauces, butter or margarine. Try lemon juice as a salad dressing. Substitute plain low-fat yogurt, blender-whipped low-fat cottage cheese, or buttermilk in recipes that call for sour cream or mayonnaise. Use skim or low-fat milk in place of whole milk in puddings, soups, and baked products.

Getting a Variety of Foods

The Dietary Guidelines say that the many nutrients you need should come from a variety of foods, not from a few highly fortified foods or supplements. A good way to ensure variety is to choose foods each day from the five major food groups. USDA has developed a daily food guide for a well-balanced diet that suggests the following:

Vegetables: 3 to 5 servings

Fruits: 2 to 4 servings

Breads, cereals, rice, pasta: 6 to 11 servings

Milk, yogurt, cheese: 2 to 3 servings

Meat, poultry, fish, dried beans and peas, eggs, nuts: 2 to 3 servings

This food guide is "a useful, simple way for women to look at their own diets and see how to improve them," says Stephenson. By choosing different foods from each group daily, the food guide can serve as the basis for the dietary guideline "eat a variety of foods," says Stephenson, and "that's a tenet of nutritional advice for all people."

Finally, the guidelines are meant for the average person, cautions Walter H. Glinsmann, M.D., FDA's associate director for clinical nutrition. "Almost nobody is average," he says. Lifestyle, genetics, and conditions such as pregnancy or disease can also affect a person's nutritional needs, he explains

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.