Nutrient glossary
What is fibre?
Fibre is the indigestible part of plants that feeds your gut bacteria, steadies digestion and helps you feel full.
Reviewed 20 July 2026. General information, not medical advice.
The short version
Fibre passes through the small intestine undigested and becomes food for the bacteria in your colon. That fermentation produces compounds linked to lower risks of heart disease, type 2 diabetes and bowel cancer. Fibre also slows how fast a meal turns into blood sugar and adds the bulk that keeps digestion regular.
It only comes from plants: whole grains, beans, lentils, vegetables, fruit, nuts and seeds. There is no fibre in meat, fish, eggs or dairy, which is why an all-animal diet needs deliberate planning.
Daily reference
30 g a day
The adult reference is 30 g a day. Most people get closer to 18 g, so the gap is usually the easiest one to close for the biggest return.
This is the fixed adult reference used across these pages. In the app, your amount adjusts to your body and way of eating.
Best food sources of fibre
Full ranking| Food | Per serving | Per 100g |
|---|---|---|
| Lentils (cooked) | 16 g | 8 g |
| Black Beans (cooked) | 15 g | 9 g |
| Chickpeas (cooked) | 12 g | 8 g |
| Pinto Beans | 12 g | 9 g |
| Kidney Beans | 10 g | 7 g |
| Butter Beans | 9 g | 7 g |
| Baked Beans | 9 g | 4 g |
| Peas | 8 g | 6 g |
Common questions
- How much fibre should I eat a day?
- The evidence-based adult reference is 30 g a day. A bowl of porridge, a tin of beans and a couple of pieces of fruit gets you most of the way.
- Does fibre count towards carbs?
- On labels and in Nutrigate, fibre is part of total carbohydrate but is subtracted when net carbs are calculated, because you do not digest it.