The Purpose Of Fiber In The Diet

Dietary fiber is sometimes referred to as roughage or bulk. It plays a number of important roles in the diet. Because fiber absorbs liquid, it is important that people consuming a high-fiber diet drink plenty of water. The Institute of Medicine recommends a daily fiber consumption of 38 grams for men and 25 grams for women under age 50, and 30 grams for men and 21 grams for women ages 50 and older.

Sources and Types

Edible plants are the primary source of fiber in the diet. There are two types of fiber: insoluble, which does not dissolve and assists with digestive health, and soluble, which dissolves in water, forming a viscous material that contributes to circulatory health. Whole-wheat products, bran, nuts and most vegetables are natural sources of insoluble fiber. Fruits, legumes and root vegetables such as apples, beans and carrots are natural sources of insoluble fiber.

Gastrointestinal Effects

Your body does not digest or absorb fiber. This allows it to move through your entire digestive system with a "cleaning" effect. Fiber softens and adds bulk to stool, allowing it pass more easily and thoroughly. This can relieve some symptoms in people suffering from irritable bowel syndrome and reduce the risk of hemorrhoids caused by straining to pass stool.

Other Benefits

Soluble fiber slows sugar absorption, helping to regulate blood sugar levels. This is particularly important for people with diabetes. It also lowers low-density lipoprotein, which accounts for levels of "bad" cholesterol. Many people find that a high-fiber diet aids in weight loss in several ways. Fibrous foods are often low-calorie per volume and help people feel full after a meal, reducing overeating. They also tend to take longer to eat, allowing your body time to alert you when you have eaten enough.

Fiber Supplements

Fiber supplements are an option for people who are concerned about digestive health but are unable to get enough dietary fiber from natural sources. Doctors may recommend fiber supplements to patients with gastrointestinal problems. The Mayo Clinic reports that there is "no evidence that long-term use of fiber supplements is harmful." Most fiber supplements are available as a powder that dissolves in water.

Effects of Inadequate Fiber

Low dietary fiber can lead to a number of health problems. It is one of the leading causes of constipation, or inability to pass an adequate bowel movement. Diverticulosis and diverticulitis are conditions affecting the colon. Both disorders are believed to be caused by a low-fiber diet. Inadequate fiber intake has also been linked with increased risk for high blood pressure, diabetes, cardiovascular disease, obesity and cancer.