WHAT IS DIETARY FIBER?
Dietary fiber is found only in plant-based foods. It is composed of a group of structurally related substances: cellulose,
hemicelluloses, lignin, gums and pectins. Good sources of dietary fiber include whole grains, vegetables, fruit, nuts
and seeds. Meat, fish, poultry, eggs, dairy products, fats, oils and sugar contain no dietary fiber.
WHY SHOULD WE INCLUDE DIETARY FIBER IN OUR DIETS?
Some of the benefits of dietary fiber are to increase fecal bulk, soften stools, stimulate the healthy movement of
foodstuffs through the digestive tract and assist the muscles of the digestive tract. Consuming high fiber foods thus
may help prevent and treat constipation. In addition, researchers have shown that dietary fiber can play an important
role in the prevention or treatment of various diseases and disorders. These include obesity, diabetes, cardiovascular
disease, colon cancer, diverticular disease and irritable bowel syndrome, as well as constipation.
WHAT ARE SOLUBLE AND INSOLUBLE FIBERS?
Dietary fiber is frequently classified as either soluble or insoluble. Soluble fibers dissolve in water and consist of pectins,
gums and some hemicelluloses. Insoluble fibers do not dissolve in water and consist of cellulose, lignin and some
hemicelluloses. Soluble fiber has been shown to be effective in reducing the risk of cardiovascular disease and
diabetes by reducing total blood cholesterol and regulating blood sugar levels. Insoluble fiber has been shown to be
effective in reducing the risk of colon cancer, preventing diverticular disease and treating constipation.
WHAT ARE SOME SOURCES OF SOLUBLE AND INSOLUBLE FIBERS?
Ideally, we should incorporate both soluble and insoluble fibers in our diets. Good sources of soluble fiber include
oats, barley, legumes (dried beans and peas) and some vegetables and fruits. Good sources of insoluble fiber include
whole grain products (breads, cereals, rice, pasta), nuts, seeds and some vegetables.
HOW MUCH DIETARY FIBER SHOULD WE CONSUME EACH DAY?
Experts are now recommending a dietary fiber intake in the range of 20 - 35 grams/day for the healthy adult. The
average American consumes between 10 - 20 grams/day - well below the current recommendations.
CAN PROBLEMS ARISE FROM EATING TOO MUCH DIETARY FIBER?
Yes. Dietary fiber, if increased suddenly, can cause gas, diarrhea and bloating. It should be added gradually, allowing
time for your body to adjust to the extra fiber. For example, begin by increasing your fiber intake to 20 grams/day;
allow a few days for adjustment, and then increase it to 25 grams/day. As you add fiber to your diet, it is very
important to drink plenty of fluids, since fiber draws water into the intestines. Health care providers recommend at
least eight glasses of water each day. Although excessive intakes of dietary fiber may interfere with the absorption of
some nutrients, moderate intakes (i.e., 20 - 35 grams/day) do not appear to pose a problem for the healthy adult.
ADDITIONAL SUGGESTIONS TO HELP ALLEVIATE CONSTIPATION
1. Eat regular meals, allowing time to completely chew food.
2. Drink plenty of non-caffeinated fluids throughout the day. Start drinking these as soon as you wake up.
3. Incorporate regular exercise on a daily basis.
4. Never resist the urge to have a bowel movement. It is important to give this immediate attention.
More information about fiber is available from the McKinley Health Resource Centers located in Room 222, McKinley
Health Center or Room 129 N at the Illini Union).