Also called: Bulk · Roughage

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Dietary Fiber

Fiber is a substance in plants. Dietary fiber is the kind you eat. It's a type of carbohydrate. You may also see it listed on a food label as soluble fiber or insoluble fiber. Both types have important health benefits.

Good sources of dietary fiber include:

  • Whole grains
  • Nuts and seeds
  • Fruit and vegetables

Dietary fiber adds bulk to your diet and makes you feel full faster, helping you control your weight. It helps digestion and helps prevent constipation. Most Americans don't eat enough dietary fiber. But add it to your diet slowly. Increasing dietary fiber too quickly can lead to gas, bloating, and cramps.

Centers for Disease Control and Prevention

It sits within Food and Nutrition.

The lead U.S. institute for this subject is the NIH Office of Dietary Supplements.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Dietary Fiber

1,008 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

Start Here

Related Issues

Medical subject headings

Clinicians and researchers index this subject under Dietary Fiber. These are the terms to use when searching medical literature.


This page is built from the MedlinePlus health topic record for Dietary Fiber, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.