Fiber overload: How excess intake impacts your body

Fiber is beneficial for most individuals, but more isn’t always better.

On average, Americans consume 16 grams of fiber a day. It is recommended that women consume 25 grams and men consume 38 grams of fiber per day. [1]. 

Hello, fiber

The fiber in plant foods is not fully digested or absorbed by the body. As a result, it aids in the digestion of food. Overconsumption of fiber can cause bloating, constipation and cramps.

Fiber can be soluble or insoluble. When mixed with liquids, soluble fiber forms a gel-like substance. It reduces LDL cholesterol levels, the “bad” cholesterol [2].

According to the National Lipid Association, soluble fiber binds to cholesterol and helps transport it out of the body [3]. Bananas, apples, oats, berries and avocados are good sources of soluble fiber.

While soluble fibers attract liquids, insoluble fibers do not. Constipation can be managed by adding bulk to the stool and moving things along. 

Additionally, it enhances insulin sensitivity. There are many sources of insoluble fiber, including nuts, seeds, corn, whole-wheat flour and fruit and vegetable skins.

How much fiber is too much fiber?

For every 1,000 calories consumed daily, 14 grams of fiber are adequate. Depending on your age, sex and medical history, the exact recommendation may differ.

Health benefits greatly from eating enough fiber. Among the benefits of eating enough fiber are:

  • Controlling cholesterol levels
  • Keeping your heart healthy
  • Maintaining blood sugar stability
  • Enhancing digestion
  • Managing constipation or preventing it
  • Promoting satiety

Keep an eye out for these signs if you seem to be consuming more fiber than usual:

Gas and bloating

Dietary Guidelines for Americans 2020-2025 report that over 90% of Americans do not consume enough fiber [4]. Gas and bloating can occur when you increase your fiber intake too rapidly.

Slowly increase your fiber intake if you’re trying to increase it. Adding a few grams of fiber a week will help.

Mineral deficiencies

Fiber inhibits the absorption of several essential minerals, including calcium, iron, magnesium and zinc. As a result, fiber prevents your body from absorbing some minerals from your food.

Symptoms like constipation, bloating, abdominal pain, irregular heartbeat, loss of appetite, muscle cramps, nausea, vomiting or numbness and tingling in your extremities could indicate a mineral deficiency. We highly suggest that you seek advice from your doctor as soon as possible to confirm your suspicion.

Constipation

For various reasons, consuming too much fiber could lead to constipation. If you’re constipated, you may have heard that increasing your fiber intake can help.

However, it’s important to gradually increase your fiber intake while also staying hydrated to prevent further constipation. Drinking enough water is also crucial since fiber absorbs water from the intestines.

Bowel obstruction

In some cases, too much fiber can cause a phytobezoar in the intestinal tract, according to a 2022 study in Nutrients [5]. Fiber builds up in the intestine, forming a ball that prevents food from passing. Due to reduced digestive efficiency and decreased elasticity of the intestinal wall, older individuals and those with certain digestive diseases may be at higher risk.

Here is The Institute of Medicine’s recommendation for daily fiber intake [1]:

Children

  • Age 0-3: 19 grams of fiber a day
  • Age 4-8: 25 grams of fiber a day

Women

  • Age 9-13: 26 grams of fiber a day
  • Age 14-18: 26 grams of fiber a day
  • Age 19-50: 25 grams of fiber a day
  • Age 50+: 21 grams of fiber a day

Men

  • Age 9-13: 31 grams of fiber a day
  • Age 14-18: 38 grams of fiber a day
  • Age 19-50: 38 grams of fiber a day
  • Age 50+: 30 grams of fiber a day

Genetics and medical history may determine the right amount of fiber for you. There is no maximum recommendation regarding how much fiber is too much. However, some evidence suggests consuming more than 70 grams of fiber daily can lead to side effects.

[1] https://journals.sagepub.com/doi/10.1177/1559827615588079
[2] https://www.cdc.gov/diabetes/library/features/role-of-fiber.html
[3] https://www.lipid.org/sites/default/files/adding_soluble_fiber_final_0.pdf
[4] https://www.dietaryguidelines.gov/sites/default/files/2021-03/Dietary_Guidelines_for_Americans-2020-2025.pdf
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9268622/

The information included in this article is for informational purposes only. The purpose of this webpage is to promote broad consumer understanding and knowledge of various health topics. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.