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Publication #FCS8793

Facts about Fiber1

Jennifer Hillan, R. Elaine Turner, and Wendy J. Dahl2

What is fiber? Why do we need it?

Fiber is found in fruits, vegetables, grains, nuts, seeds, and beans. Unlike sugar and starches, fiber is a carbohydrate that we cannot digest. Adequate fiber intake can help us maintain good health in a number of ways (Institute of Medicine, 2005).

  • Some types of fiber help slow down the body's absorption of glucose (sugar). This can help in control of blood glucose.

  • Some types of fiber help to reduce blood cholesterol. This can help reduce the risk of heart disease.

  • Other types of fiber help keep our bowel function regular.

  • Higher fiber foods may help us feel full or satisfied longer after eating. This may help with weight control.

Foods contain different types of fiber. It's important to eat a wide variety of plant foods to get the most health benefits from fiber. Higher intakes of fiber from plant foods are associated with a reduced risk of heart disease, type 2 diabetes, and cancer (Dahl & Stewart, 2015).

What happens if we don't get enough fiber?

Fiber helps to form larger, softer stools that pass with regularity. Without enough fiber, we may suffer from constipation and hemorrhoids.

How much fiber do we need?

Recommendations for fiber intake are based on studies of the amounts needed to reduce heart disease risk. This level of fiber intake will also help prevent constipation. Table 1 lists the recommended Adequate Intakes (AI) for fiber (Institute of Medicine, 2005).

How can we get enough fiber?

Fruits, vegetables, beans, nuts, seeds, and whole grains provide fiber. Fruits and vegetables with edible skins and seeds are good choices for fiber. Most juices contain almost no fiber, so choose whole fruits and vegetables more often. Make sure that at least half of your daily grain servings are whole grain. Look for products that have a whole grain such as whole wheat, brown rice, or whole rye first on the ingredient list, as these will usually contain the most fiber.

For packaged foods, read the Nutrition Facts Panel and choose foods with more than 2 g of fiber per serving. Some foods, such as bread and baked goods, have added fiber. For more information about foods with added fiber see EDIS publication FS235, Shopping for Health: Foods with Added Fiber (FSHN13-11) at http://edis.ifas.ufl.edu/pdffiles/FS/FS23500.pdf.

What about fiber supplements?

It's best to get fiber from food rather than from supplements. Not only are foods more enjoyable to eat, but they also are packed with nutrients needed for good health, such as vitamins and minerals. Fiber supplements usually don't have these added benefits. If you think you need a fiber supplement, first talk to your healthcare provider.

For more information on fiber supplements, see EDIS publication FS162, Guide to Fiber Supplements (FSHN11-01) at http://edis.ifas.ufl.edu/fs162.

How much fiber is too much?

There is no upper limit for fiber from whole grains, fruits, vegetables, nuts, seeds, and beans (Institute of Medicine, 2005).Very high intakes of fiber may result in gas, bloating, and distention in some people.

Where can I get more information?

The Family and Consumer Sciences (FCS) agent at your local UF/IFAS Extension office may have more written information and classes for you to attend. Also, a registered dietitian/nutritionist (RDN) can provide reliable information to you.

A related EDIS publication—FS161, Shopping for Health: Whole Grains (FSHN10-13)—is available at http://edis.ifas.ufl.edu/fs161.

References

Dahl, W. J., & Stewart, M. L. (2015). Position of the Academy of Nutrition and Dietetics: Health implications of dietary fiber. J Acad Nutr Diet, 115(11), 1861–1870. doi:10.1016/j.jand.2015.09.003

Institute of Medicine, Food and Nutrition Board. (2005). Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (macronutrients). Washington, D.C.: National Academy Press.

Tables

Table 1. 

Fiber recommendations.

Life Stage

AI Amount

(grams [g] of fiber per day)

Children, ages 1–3

19

Children, ages 4–8

25

Females, ages 9–13

26

Females, ages 9–13

26

Males, ages 9–13

31

Males, ages 14–18

38

Men, ages 19–50

38

Men, ages 51+

30

Women, ages 19–50

25

Women, ages 51+

21

Pregnancy

28

Breastfeeding

29

Source: Institute of Medicine (2005)

Table 2. 

Fiber contents of selected foods.

Food

Fiber

(grams)

Lentils, cooked, ½ cup

8

Peanuts, boiled, ½ cup shelled

8

Black beans, cooked, ½ cup

8

Figs, dried, ½ cup

7

Wheat-bran flakes cereal, 1 cup

7

Prunes, dried or canned, ½ cup

6

Orange, raw, 1 large

4

Popcorn, air-popped, 3 cups

4

Potato, baked, with skin, 1 medium

4

Barley, pearled, cooked, ½ cup

3

Oatmeal, cooked, ½ cup

2

Whole wheat bread, 1 slice

2

Footnotes

1.

This document is FCS8793, one of a series of the Department of Family, Youth and Community Sciences, UF/IFAS Extension. Original publication date August 2006. Revised February 2015 and September 2018. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication.

2.

Jennifer Hillan, MSH, RD, LD/N, former ENAFS nutrition educator/trainer, Department of Family, Youth and Community Sciences; R. Elaine Turner, PhD, professor and dean, College of Agricultural and Life Sciences; and Wendy J. Dahl, PhD, associate professor, Food Science and Human Nutrition Department; UF/IFAS Extension, Gainesville, FL 32611.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.