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What Is Fiber?
Dietary fibers are forms of carbohydrates found in plants that cannot be digested by humans. All plants contain fiber, including fruits, vegetables, grains, and legumes. Fiber is often classified into 2 categories: soluble and insoluble.
- Soluble fiber draws water into the bowel and can help slow digestion. Examples of foods that are high in soluble fiber include oatmeal, oat bran, barley, legumes (beans and peas), apples, and strawberries.
- Insoluble fiber speeds digestion and can add bulk to the stool. Examples of foods that are high in insoluble fiber include whole-wheat products, wheat bran, cauliflower, green beans, and potatoes.
Why Follow a High-Fiber Diet?
A high-fiber diet is often recommended to prevent and/or treat constipation, hemorrhoids, diverticulitis, irritable bowel syndrome, and colon cancer.
How Much Fiber Should I Eat?
A high-fiber diet should contain 20-35 grams of fiber a day. This is actually the amount recommended for the general adult population. Most Americans eat only 15 grams of fiber per day.
Digestion of Fiber
Eating a higher-fiber diet than usual can take some getting used to by your body’s digestive system. To avoid the side effects of sudden increases in dietary fiber (like gas, cramping, bloating, and diarrhea), increase fiber gradually and be sure to drink plenty of fluids every day.
Tips for Increasing Fiber Intake
- Whenever possible, choose whole grains over refined grains (brown rice instead of white rice, whole-wheat bread instead of white bread).
- Include a variety of grains in your diet, such as wheat, rye, barley, oats, quinoa, and bulgur.
- Eat more vegetarian-based meals. These include black bean burgers, eggplant lasagna, and veggie tofu stir-fry.
- Choose high-fiber snacks, such as fruits, popcorn, whole-grain crackers, and nuts.
- Make whole-grain cereal or whole-grain toast part of your daily breakfast regimen.
- When eating out, whether ordering a sandwich or dinner, ask for extra vegetables.
- When baking, replace part of the white flour with whole-wheat flour. Whole-wheat flour is particularly easy to incorporate into a recipe.
High-Fiber Diet Eating Guide
|Food Category||Foods Recommended||Notes|
|Meats and Beans||
|Fats and Oils||
|Snacks, Sweets, and Condiments||
Eat Right—Academy of Nutrition and Dietetics
US Department of Agriculture
Dietitians of Canada
Dietary, functional, and total fiber. National Institute of Medicine website. Available at: http://www.nap.edu/openbook.php?record%5Fid=10490&page=339. Accessed August 6, 2015.
Fiber. Harvard School of Public Health website. Available at: http://www.hsph.harvard.edu/nutritionsource/carbohydrates/fiber. Accessed August 6, 2015.
Fiber. The Linus Pauling Institute Micronutrient Information Center website. Available at: http://lpi.oregonstate.edu/mic/other-nutrients/fiber. Accessed August 6, 2015.
Nutrition Care Manual. Academy of Nutrition and Dietetics Eat Right website. Available at: http://nutritioncaremanual.org. Accessed August 6, 2015.
Shield J, Mullen MC. Patient education materials. Supplement to the Manual of Clinical Dietetics. 3rd ed. Chicago, IL: American Dietetic Association; 2001.
Slavin JL. Position of the American Dietetic Association: Health implications of dietary fiber. J Am Diet Assoc. 2008;108(10): 1716-1731.
12/9/2011 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Aune D, Chan DS, Lau R, et al. Dietary fibre, whole grains, and risk of colorectal cancer: Systematic review and dose-response meta-analysis of prospective studies. BMJ. 2011;343:d6617.
- Reviewer: Dianne Scheinberg Rishikof MS, RD, LDN
- Review Date: 08/2015
- Update Date: 06/09/2016