Fiber, a natural substance found in plant foods such as berries, beans, nuts, oats and bran, is an important component of a healthy diet. Known for its beneficial effects on blood cholesterol levels, fiber is also credited with promoting intestinal health and regular bowel movements as well as regulating blood sugar and appetite control.

Various studies have shown that a diet rich in fiber appears to reduce the risk of digestive system disorders including constipation, diarrhea, gallstones, diverticular disease, irritable bowel syndrome and colorectal cancer. Other conditions for which fiber appears to reduce risk include heart disease, diabetes and obesity.

High-fiber foods are a rich source of vitamins and minerals, and are generally low in total fat, cholesterol and sodium. Foods high in fiber generally have few calories. They also contribute to a feeling of fullness.

According to the American Dietetic Association, most people consume only about 11 grams of dietary fiber per day. In addition, less than 15 percent of Americans include at least one serving of whole grains in their daily diets. This amount is about half the intake recommended by health experts. The Food and Nutrition Board of the U.S. National Academy of Sciences recommends that people consume 25 to 35 grams of fiber a day. To get adequate fiber, health experts recommend that people consume a variety of fruits, vegetables and whole-grain products daily.