Also called roughage; which is, the ingestible portion of plant foods that pushes food through the digestive system, absorbing water and easing elimination.

It has been proven that dietary fiber and bulk are important to the diet. Fiber and bulk producing foods contain substances that pass through the digestive tract without being absorbed, have an intestinal cleansing action and keep the digestive tract clean.

Foods that are fibrous move through the digestive tract due to the peristaltic action of the alimentary canal, and take with them many toxic substances that would otherwise become lodged. If these harmful substances are not eliminated by the body, disease results.

Fiber is divided into two categories - water soluble (dissolves in water) and water insoluble (does not dissolve in water). Both types are present in all plant foods with varying levels of each.

Eating fiber has many health benefits. The consumption of soluble fiber has been shown to protect you from developing heart disease by reducing your cholesterol levels and stabilizing blood sugar levels. The consumption of insoluble fiber may help prevent constipation, colitis, colon cancer, hemorrhoids, varicose veins, obesity and many other diseases.

Whole foods such as fruits and vegetables, nuts, seeds and whole grains contain bulk and fiber. Oat bran and rice bran are wise additions to the diet for added roughage.

In addition, psyllium seeds contain a high level of soluble dietary fiber. The husk swell (when it comes into contact with water) forming a gelatinous mass that helps to keep the stool soft and hydrated and acts as a natural broom that sweeps the colon walls. Psyllium has been studied for its ability to promote colon health.

Because the refining process removes much of the natural fibrous substances from our foods, the American diet is lacking in fiber.

There are seven forms of fiber: pectin, bran, cellulose, hemicellulose, lignin, gums and mucilages. Each form has its own function.

The function of pectin:

• slows the absorption of food after meals

• removes unwanted metals and toxins

• valuable in radiation therapy

• helps lower cholesterol

• reduces the risk of heart disease and gallstones

Pectin is found in apples, pears, lima beans, carrots, broccoli, peas, whole grains, Brazil nuts, green beans and beets.

The function of oat and rice bran:

• helps to lower cholesterol

The function of cellulose:

• good for hemorrhoids, varicose veins, colitis, constipation and the removal of cancer causing substances from the colon wall.

Cellulose is a non-digestible carbohydrate found in the outer layer of fruits and vegetables. It is found in the same food list as pectin.

The function of hemicellulose:

• good for weight loss, constipation, colon cancer and controlling carcinogens in the intestinal tract.

Hemicellulose is an indigestible complex carbohydrate that absorbs water. It is found in apples, beets, whole grain cereals, cabbage, bananas, beans, corn, peppers, greens and pears.

The function of lignin:

• good for lowering cholesterol levels

• preventing gallstone formation

• beneficial to those with diabetes or colon cancer

It is found in carrots, green beans, peas, whole grains, Brazil nuts, peaches, tomatoes, strawberries and potatoes.

The function of gums and mucilages:

• both help to regulate blood glucose levels

• both help in removal of toxins

Start with small amounts of roughage and gradually increase your intake until stools are the proper consistency. Those who suffer from Crohn's disease should avoid supplements and consume natural fibrous foods.

Many of the foods that contain fiber are also rich in antioxidants. Eat at least 25 grams daily (40 grams is ideal) and at least 8 glasses of water a day to insure that the fiber moves through your system properly. Be sure to eat both the soluble (like that found in oat bran) and insoluble fibers (the kind in whole wheat products).

Fiber can decrease the absorption of any medicine. Take all supplements and prescription medicine at least three hours before or after using dietary fiber supplements.