By: Sierra Girton, MS, CSCS, USAW | Purdue Dietetics Intern

What is Fiber?

Fiber is a carbohydrate the body can’t digest but is essential for normal and regular digestion. Fiber helps the body digest other carbohydrates such as sugar, allowing the body to keep hunger and blood sugar levels in check. There are also two types of fiber: soluble and insoluble. Soluble fiber absorbs water and slows digestion and insoluble fiber adds bulk to digested food and allows food to pass more quickly through the digestive tract. Soluble fibers promote cardiovascular (heart) health and insoluble fiber promotes gastrointestinal (digestive system) health. The current Adequate Intake for fiber is 25g for adult women and 38g for adult men. The adequate intake is based on the median fiber intake to achieve the lowest risk of coronary heart disease (strokes). The daily average intake for fiber in the United States is currently 17g/day meaning and only 5% of the population is consuming enough daily fiber!

Fun Fact: Fiber is not considered a nutrient because a deficiency state has not been defined.

What foods are good sources of fiber?

There are many different foods that contain fiber, but whole fruits, raw vegetables and whole grains are usually in favor of containing a good amount of fiber. Surprisingly, another good source of fiber can come from beans and lentils (especially cooked split peas, a food bank staple item). Foods high in fiber also contain many vitamins and minerals that are needed to maintain good human health. Making half of your plate fruits and vegetables and making half of your grains whole grains is a good way to ensure you are consuming enough daily fiber.

Fiber and Disease Prevention

Fiber can help with keeping your health up to par and aid in preventing chronic disease conditions. These diseases include heart disease, type 2 Diabetes, diverticulitis (inflammation of the colon), colon cancer and possibly breast cancer. Higher daily fiber intake can lower your risk of developing high blood pressure, high insulin levels, excess weight around the midsection, and increase your levels of HDL cholesterol (the good cholesterol J).

So, how does fiber intake make your digestion more regular?

High fiber foods tend to make you feel more full, lessening the chance you reach for those less-healthy foods. Fiber also helps regulate digestion by pushing food through your digestive system more quickly. This will lessen the chance of you feeling boated. Fiber also helps absorb water in the digestive tract allowing food to have more room to flow through. So, as you increase your fiber intake, you should also increase your fluid intake.

Can you consume too much fiber?

Currently, there is no intake level of fiber that has shown to cause negative effects on digestive system function. However, if your current eating habits do not include enough fiber you should slowly increase your daily consumption to avoid excessive gas, bloating and diarrhea. A good rule of thumb is to increase your fiber intake by no more than 5g/week until the Adequate Intake is reached.


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115(11), 1861–1870. doi: 10.1016/j.jand.2015.09.003

(2019, June 4). Fiber. Retrieved from