High-Fiber DietManual of Clinical Nutrition Management D- 7 Copyright © 20 13 Compass Group, Inc.
daily consumption of dietary fiber is encouraged from food sources such as whole grains, fruits, and
vegetables (21).
Weight management: Dietary fiber intake from whole foods or supplements may have some benefit in
terms of weight loss and other health outcomes associated with weight loss (Grade III) (1). Benefits may occur
with daily fiber intakes of 20 to 27 g from whole foods or up to 20 g from supplements (Grade III) (1). Fiber acts
as a physiological obstacle to energy intake by displacing energy and nutrients from the diet, increasing the
expansion of the stomach leading to increased satiety and feelings of fullness, and reducing the absorption
efficiency of the small intestine (1). High-fiber foods promote energy balance by providing a significant
amount of volume and low-energy density (1).
Cancer: People who eat a greater amount of fruits and vegetables have about one half the risk of developing
cancer and a lower mortality rate from cancer (22). Evidence that a high-fiber diet decreases the risk of certain
cancers, including large bowel cancers (colon and rectum) and breast cancer, remains inconclusive (1).
Although dietary fiber intake may not protect against colorectal cancer in prospective studies, some support
exists for the protective properties of whole-grain intake (1,23). There is evidence that vegetables, fruits, and
whole grains reduce the risk of chronic diseases including cancer, which provides support for the use of a
high-fiber diet in reducing cancer risk (1,22).
Use in enteral formulas: Two types of enteral formulas that contain dietary fiber are currently marketed:
blended formulas made from whole foods and formulas supplemented with purified fiber sources (eg, oat,
pea, hydrolyzed guar gum, and sugar beet fiber) (1). Dietary fiber added to enteral formulas is thought to aid
in normalizing bowel function and reduce the incidence of diarrhea. However, there is no conclusive
evidence that fiber-containing enteral formulas prevent diarrhea in tube-fed patients (1). A recent addition to
enteral formulas is fructooligosaccharides, which are short-chain oligosaccharides (usually 2 to 10
monosaccharide units). Because they are not digested in the upper digestive tract, fructooligosaccharides
have some of the same physiologic effects as soluble fiber (24). Fructooligosaccharides are rapidly fermented
by intestinal bacteria that produce short-chain fatty acids, which stimulate water and electrolyte absorption
and should aid in the treatment of diarrhea. Although fructooligosaccharides are a preferred substrate for
Bifidobacteria, they are not used by potentially pathogenic bacteria, thus helping to maintain and restore the
balance of healthy gut flora (1). Fructooligosaccharides are not isolated by currently accepted methods to
measure dietary fiber, so they cannot technically be called dietary fiber (5). The Association of Official
Analytical Chemists has developed newer methods to analyze fructooligosaccharides (1).
Contraindications
Diverticulitis: A high-fiber diet may be contraindicated when inflammation has caused the narrowing or
blockage of the intestinal lumen or during acute diverticulitis (9). However, this recommendation is based on
individual tolerance.
Infants and children: The American Academy of Pediatrics does not encourage the addition of high-fiber
foods to the diets of infants younger than 1 year old. High-fiber foods are filling but contain little energy,
potentially causing reduced energy intakes in infants, whose stomach capacities are naturally small.
According to the American Academy of Pediatrics, the daily fiber intake of children 2 years and older should
be an amount equal to or greater than their age plus 5 g (1).
Phytobezoar formation: Phytobezoars are masses of vegetable matter that become trapped in the stomach.
Individuals who experience decreased gastric motility or emptying, such as diabetic gastroparesis, or
individuals who have undergone surgical procedures for stomach cancer or peptic ulcer disease may be
susceptible (1,25,26). These individuals should be advised to avoid the following foods implicated in
phytobezoar formation: apples, berries, brussels sprouts, coconuts, figs, green beans, oranges, persimmons,
and potato peels or highly viscous over-the-counter fiber supplements such as glucomannan (1,25,26).
Nutritional Adequacy
The diet can be planned to meet the DRIs as outlined in Section IA: Statement on Nutritional Adequacy.
How to Order the Diet
Order as “High-Fiber Diet.”