Dietary fiber

What it is

Dietary fiber is a carbohydrate found in plant foods. It comes from fruits, vegetables, grains, beans, nuts and seeds. Some fiber dissolves in water and some does not. It is not broken down by our body enzymes.

What it does

It adds bulk to waste and helps bowel movements. It helps food move through the digestive tract. It feeds helpful bacteria that live in the gut. It can help you feel full after eating.

How much people need

• FDA Daily Value for dietary fiber: 28 g. It is a reference amount used on Nutrition Facts labels, not a personal target. Source: US FDA.
• WHO: adults and children over 10 should aim for at least 25 g of naturally occurring dietary fibre a day. Source: WHO.

Common myths

• Myth: Fiber is the same as a vitamin or mineral. Truth: Fiber is a carbohydrate, not a vitamin or mineral.
• Myth: All fiber comes from whole grain bread and cereal. Truth: Fiber also comes from fruits, vegetables, beans, nuts and seeds.

Sources and background

The sections on what it is, what it does and the myths are general background from NIH MedlinePlus: Dietary Fiber, checked on 29 October 2026. The intake figures above carry their own sources.