Background

The high fiber diet incorporates consuming a larger amount of foods that have high dietary fiber content. Dietary fiber, also referred to as roughage or bulk, is the part of a plant that cannot be digested or absorbed by the body. Dietary fiber exists in soluble and insoluble forms. Soluble fiber can be dissolved in water and is fermented by bacteria in the colon. It can be found in foods such as oat bran, apples, citrus, pears, peas, beans, potatoes, seeds, oranges, grapefruit and psyllium. Insoluble fiber cannot be dissolved in water and is not affected by bacteria in the colon. It is found in wheat bran, corn bran, nuts, cabbage, and root vegetables. Animal products such as meat, fish, eggs, or dairy do not contain fiber.

According to the American Dietetic Association, the average American eats only about 12-17 grams of fiber per day, while the recommended amount is 20-35 grams per day. Only about 1/4 of this average daily intake is soluble fiber; therefore, the average American is eating only 3-4 grams of soluble fiber per day, which is well below the recommended amount of 5-10 grams of soluble fiber.

People use this for...

Effectiveness Effectiveness definitions

The high fiber diet involves increasing the intake of foods high in dietary fiber foods such as barley, psyllium, bran, oats, etc. See specific monographs of dietary fiber containing foods for effectiveness information.

Natural Medicines rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

Dosing & administration

Adverse effects

General: People who typically eat low fiber diets may experience flatulence, bloating and occasionally diarrhea when they begin to eat large amounts of fiber. These symptoms typically subside after the body adjusts to the increased fiber intake.

Gastrointestinal: Bloating, diarrhea, and flatulence have been reported after starting a high fiber diet.

Interactions with pharmaceuticals

None known.

Interactions with herbs & supplements

The high fiber diet involves increasing the intake of foods high in dietary fiber foods such as barley, psyllium, bran, oats, etc. See specific monographs of dietary fiber containing foods for information regarding interactions.

Interactions with foods

The high fiber diet involves increasing the intake of foods high in dietary fiber foods such as barley, psyllium, bran, oats, etc. See specific monographs of dietary fiber containing foods for information regarding interactions.

Interactions with lab tests

The high fiber diet involves increasing the intake of foods high in dietary fiber foods such as barley, psyllium, bran, oats, etc. See specific monographs of dietary fiber containing foods for information regarding interactions.

Interactions with diseases

The high fiber diet involves increasing the intake of foods high in dietary fiber foods such as barley, psyllium, bran, oats, etc. See specific monographs of dietary fiber containing foods for information regarding interactions.

Mechanism of action

Insoluble fiber adds bulk and helps retain water in waste mass moving through the colon, resulting in softer and larger stool. Theoretically, this may help with constipation, bowel regularity, and help with other digestive conditions.

Soluble fiber is dissolved in water and forms a jelly-like bulk inside the small intestine, which theoretically helps to lower cholesterol and reduce blood sugar by slowing gastric emptying. Soluble fibers act mostly in the small intestine because they are fermented in the large intestine through bacterial action.