Dietary Fibre: The Practical To-Do List
Dietary Fibre: what is worth doing, what is worth avoiding, and when to stop and see a doctor.
The parts of plant food the small intestine cannot digest, which pass through to the colon. 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.
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 speak to a doctor" below apply to you.
Do
- 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
Do not
- 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
The numbers behind the list
Those two lists follow from the published figures here.
| 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 |
If you change one thing
Swap white bread, rice and pasta for wholegrain versions of the same meal. That one first, and the others when you get to them.
Where to go next
- Dietary Fibre in Five Minutes
- Dietary Fibre: What Published Guidance Supports
- Dietary Fibre — the reference entry
- Dietary Protein: What the Evidence Actually Says
- The Evidence on Dietary Salt, Without the Hype
When to speak to a doctor
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.
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