Eating fiber is extremely important for maintaining one’s health. However, the daily average fiber intake for children and adults in the United States is far below the recommended levels. A high consumption of dietary fiber has shown to significantly reduce the risk of developing coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal illnesses.

Increased intake of soluble fiber helps improve blood sugar and insulin sensitivity in non-diabetic and diabetic individuals. Fiber supplementation in obese individuals significantly enhances weight loss. Studies have also shown that a high fiber diet, as part of a balanced eating model, may help prevent some long-term diseases like diverticulitis, constipation, and even some types of cancer. 

Types of Fiber:

There are two types of fiber: soluble fiber and insoluble fiber. Sources of soluble fiber include avocados, pears, peas, beans, oats, barley, apples with skin, oranges, prunes, strawberries, broccoli, and cauliflower. Foods that are great sources of insoluble fiber include turnips, beets, cauliflower, cabbage, Brussels sprouts, carrots, whole-wheat products, wheat bran, corn bran, cauliflower, green beans, and broccoli.

Soluble fiber dissolves in water to create a gel-like substance, slowing the emptying of the stomach. Soluble fiber can bind to the fatty substance cholesterol and promote its secretion, which helps lower the low-density lipoprotein (“bad”) cholesterol. Sugar absorption is also delayed by this type of fiber, which helps manage blood sugar levels.

Insoluble fiber is known as “roughage” and does not dissolve in water. However, insoluble fiber acts like a laxative, aiding in the passage of food through the stomach. Allowing food to pass possibly aids in preventing harmful substances from lingering in the intestines. Insoluble fiber, along with water, adds bulk to food and softness the stool, preventing constipation.

How Much Fiber Does One Need?

It is recommended by the Institute of Medicine that individuals consume the total dietary fiber amount, which is roughly between 25-40 grams, depending on the age and sex of the individual. The goal is to eat both soluble and insoluble fiber because both forms of fiber are significant and contain many health benefits. Regular intake of foods high in fiber can help one attain the goals of a well-balanced diet.

It is recommended to not take too much dietary fiber. Even though foods with fiber does help individuals with weight loss and heart disease, consuming more than 50-60 grams of dietary fiber can reduce the amount of vitamin and mineral absorption in the body. Also, excessive amounts of fiber can result in digestion-related problems such as gas, diarrhea, and bloating. Therefore, it is recommended to increase one’s dietary intake gradually. A sudden increase of high fiber foods can cause diarrhea and bloating. In addition, while increasing fiber intake, the amount of water intake should also be proportionately increased. This will help insoluble fiber expand in the stomach and give the feeling of fullness for a longer period of time.

Additional Resource:

Dietary Guidelines for Americans, 2010. U.S. Department of Health and Human Services. http://www.cnpp.usda.gov/DGAs2010-PolicyDocument.htm. (accessed Aug. 22, 2012)

Dietary Reference Intake. (n.d.). Retrieved December 2, 2014, from http://www.nal.usda.gov/fnic/DRI/DRI_Energy/energy_full_report.pdfDietary Reference Intake. (n.d.). Retrieved December 2, 2014, from http://www.nal.usda.gov/fnic/DRI/DRI_Energy/energy_full_report.pdf

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Marshall JR. Nutrition and colon cancer prevention. Current Opinion in Clinical Nutrition & Metabolic Care. 2009;12:539.

Park Y, et al. Dietary fiber intake and risk of colorectal cancer. JAMA. 2005;294:2849.

Post, R. E., Mainous, A. G., King, D. E., & Simpson, K. N. (2012). Dietary fiber for the treatment of type 2 diabetes mellitus: a meta-analysis. The Journal of the American Board of Family Medicine, 25(1), 16-23.

Schatzkin A, et al. Dietary fiber and whole-grain consumption in relation to colorectal cancer in the NIH-AARP Diet and Health Study. American of the Journal Clinical Nutrition. 2007;85:1353.

Slavin JL. Position of the American Dietetic Association: Health implications of dietary fiber. Journal of the American Dietetic Association. 2008;108:1716.

Smith, U. (1986). Dietary fibre, diabetes and obesity. International journal of obesity, 11, 27-31.

Streppel, M. T., Ocké, M. C., Boshuizen, H. C., Kok, F. J., & Kromhout, D. (2008). Dietary fiber intake in relation to coronary heart disease and all-cause mortality over 40 y: the Zutphen Study. The American journal of clinical nutrition, 88(4), 1119-1125.

Threapleton, D. E., Greenwood, D. C., Evans, C. E., Cleghorn, C. L., Nykjaer, C., Woodhead, C., ... & Burley, V. J. (2013). Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ: British Medical Journal, 347.

Threapleton, D. E., Greenwood, D. C., Evans, C. E., Cleghorn, C. L., Nykjaer, C., Woodhead, C., ... & Burley, V. J. (2013). Dietary Fiber Intake and Risk of First Stroke A Systematic Review and Meta-Analysis. Stroke, 44(5), 1360-1368.

Helpful Peer-Reviewed Medical Articles:

Tabas, G., Beaves, M., Wang, J., Friday, P., Mardini, H., & Arnold, G. (2004). Paroxetine to treat irritable bowel syndrome not responding to high-fiber diet: a double-blind, placebo-controlled trial. The American journal of gastroenterology, 99(5), 914-920.

King, D. E., Egan, B. M., Woolson, R. F., Mainous, A. G., Al-Solaiman, Y., & Jesri, A. (2007). Effect of a high-fiber diet vs a fiber-supplemented diet on C-reactive protein level. Archives of Internal Medicine, 167(5), 502-506.

Peery, A. F., Barrett, P. R., Park, D., Rogers, A. J., Galanko, J. A., Martin, C. F., & Sandler, R. S. (2012). A high-fiber diet does not protect against asymptomatic diverticulosis. Gastroenterology, 142(2), 266-272.

Bennett, N., Greco, D. S., Peterson, M. E., Kirk, C., Mathes, M., & Fettman, M. J. (2006). Comparison of a low carbohydrate–low fiber diet and a moderate carbohydrate–high fiber diet in the management of feline diabetes mellitus. Journal of Feline Medicine & Surgery, 8(2), 73-84.

Parisi, G. C., Zilli, M., Miani, M. P., Carrara, M., Bottona, E., Verdianelli, G., ... & Tonon, A. (2002). High-fiber diet supplementation in patients with irritable bowel syndrome (IBS): a multicenter, randomized, open trial comparison between wheat bran diet and partially hydrolyzed guar gum (PHGG). Digestive diseases and sciences, 47(8), 1697-1704.