Dietary Fibre
The parts of plant food the small intestine cannot digest, which pass through to the colon.
Last revised
Key takeaways
- UK recommendation, adults: 30g a day
- Average UK intake: around 20g a day
- Most useful single change: Swap white bread, rice and pasta for wholegrain versions of the same meal.
- Commonest mistake: Doubling your intake in one day, which reliably causes bloating and wind.
- See a doctor if any of the signs under "When to get help" below apply to you.
Why it matters
Higher intakes are consistently associated with lower rates of coronary heart disease, type 2 diabetes and bowel cancer, and UK adults eat about two thirds of the recommended amount.
The numbers, in one place
| Measure | Figure |
|---|---|
| UK recommendation, adults | 30g a day |
| Average UK intake | around 20g a day |
| Half a tin of baked beans | about 5g |
| Two slices of wholemeal bread | about 5g, against 2g for white |
| Sensible rate of increase | about 5g a week |
What helps
- Swap white bread, rice and pasta for wholegrain versions of the same meal
- Leave the skins on potatoes, apples, pears and carrots
- Keep tinned beans, chickpeas and lentils in the cupboard
- Increase fluid as you increase fibre, since fibre works by holding water
What to avoid
- Doubling your intake in one day, which reliably causes bloating and wind
- Fibre supplements when food does the job more cheaply
- Assuming "multigrain" means wholegrain; check the first ingredient says whole
Where to go next
- Dietary Fibre: Common Myths and What Guidelines Say
- Dietary Fibre for Beginners: Where to Start
- Dietary Protein: What the Evidence Actually Says
- The Evidence on Dietary Salt, Without the Hype
When to get help
See a GP rather than adding fibre for a persistent change in bowel habit lasting three weeks or more, blood in your stool, unexplained weight loss, or ongoing abdominal pain. People with inflammatory bowel disease or a diagnosed stricture should take advice from their own clinical team.
Where this comes from
- NHS — How to get more fibre into your diet
- Scientific Advisory Committee on Nutrition — Carbohydrates and Health
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.