Which Foods Are High in Fibre? A UK Table by Portion

The foods highest in fibre per UK portion are pulses and wholegrains: 120 g of red kidney beans boiled from dried gives about 13.3 g (8.2 g canned), 200 g of baked beans about 9.8 g, 120 g of boiled lentils about 8.9 g, 180 g of wholewheat spaghetti about 7.6 g, two slices of wholemeal bread about 5.6 g and 40 g of bran flakes about 5.4 g. Per 100 g, bran cereals, dried fruit, nuts and seeds lead; a banana or an apple gives about 1 g a portion, and eggs, meat, fish and dairy contain no fibre at all.^{1, 2} "High fibre" on a label means 6 g or more per 100 g; the adult target is 30 g a day against an average of 16.4 g in the 2019 to 2023 national survey.^{1, 3, 4}

Which foods are highest in fibre per UK portion?

The table ranks everyday foods by fibre per realistic UK portion, with the per-100 g figure beside it, because the two orders differ: almonds are 12.5 g per 100 g but a 20 g handful gives 2.5 g, while a baked potato is low per 100 g and still gives 5.7 g.²

Which fruit has the most fibre, and which the least?

Dried fruit leads per 100 g: ready-to-eat dried figs at about 10 g, dates at 7.5 g and ready-to-eat dried apricots at 5.3 g, so a 30 g portion gives 1.6 to 3 g, though the NHS advises keeping dried fruit to mealtimes.^{1, 2} Among fresh fruit, raspberries and strawberries (about 3.7 to 3.8 g per 100 g) and pears with skin (2.7 g) are the better sources; bananas (1.4 g) and apples (1.2 g) sit near the bottom, so "one banana a day" supplies about a gram.² Clear juice supplies almost none, and prune juice only a trace: its bowel effect is usually put down to the sugar alcohol sorbitol, about 6 g per 100 g of juice, against 5.2 g of fibre and about 15 g of sorbitol in 100 g of prunes.^{2, 5}

Is wholemeal bread high in fibre, and does toasting reduce it?

Wholemeal bread is high in fibre on the NHS definition at about 7.0 g per 100 g, so two slices give about 5.6 g.^{1, 2} Toasting does not reduce fibre: heat drives off water, and the fibre in the slice is unchanged. Bran-based and shredded wholewheat cereals run from about 12 to 24.6 g per 100 g; a 40 g bowl of bran flakes gives about 5.4 g and 45 g of porridge oats about 3.5 g.^{1, 2} Oats carry beta-glucan, the gel-forming fibre behind the cholesterol wording; wheat carries bran, the bulking fibre behind the transit wording.⁶

How do you build fibre into each meal?

Thirty grams divides into about 8 g at breakfast, 10 to 12 g at lunch and at dinner, and 2 to 5 g in snacks, as in the NHS's own examples: wholemeal toast with peanut butter and an orange (about 8.3 g), wholemeal spaghetti with a lentil and tomato sauce (about 11 g), and grilled chicken with a skin-on baked potato, carrots and green beans (about 11.2 g).¹ The swaps that do most work: wholegrain pasta for white; wholemeal bread for white; 120 g of lentils, chickpeas or beans added to a soup, curry or chilli (8 to 13 g); wheat bran flakes or porridge in place of a low-fibre cereal; 80 g of berries.² Add one swap a week with a glass more water a day, because fibre without fluid can make things worse; gel-forming foods (oats, pulses, fruit) suit a sensitive gut better than bran, which is the order to add them in.⁶

How on earth do you eat 30 g of fibre in a day? A January day

Searches for high-fibre foods nearly double in January; the question behind them is arithmetic. A day from the table above, all approximate:²

• Breakfast: porridge from 45 g of oats (3.5 g) with 80 g of frozen raspberries (3.0 g) and 20 g of almonds (2.5 g): about 9 g
• Lunch: lentil soup with 120 g of lentils (8.9 g) and 80 g of carrots (3.1 g), with two slices of wholemeal bread (5.6 g): about 18 g
• Dinner: kidney-bean chilli with 120 g of canned beans (8.2 g) and 80 g of green beans (3.3 g): about 12 g
• Snack: a pear (2.2 g): about 40 g for the day

That overshoots on purpose, to show where to cut: without the bread the day lands at about 35 g, and without the almonds too at about 32 g. On 1,200 to 1,500 calories the same day works if the pulses, vegetables and berries stay and the bread, pasta and nuts go; on labels the yardstick is 3 g of fibre per 100 kcal, the "high fibre" threshold.³ If your app gives different numbers, databases differ: the UK target uses the AOAC method, which counts resistant starch that the older non-starch polysaccharide method left out; cooking changes the figure (raw broccoli is 4.0 g per 100 g, boiled 2.8 g); and US databases differ again. The reference that settles it is McCance and Widdowson's dataset, CoFID.^{2, 4} How much fibre you need a day explains where 30 g comes from, the figures for children, and what fibre does in numbers.

Which fibre foods help constipation most?

Two foods have head-to-head trial evidence. In a US trial, two green kiwifruit a day, 100 g of prunes a day and 12 g of psyllium a day all raised complete bowel movements over four weeks, with kiwi the best tolerated and psyllium the least; in a 40-person crossover, 100 g of prunes a day gave 3.5 complete movements a week against 2.8 on 22 g of psyllium.^{8, 9} For packaged foods, the GB register authorises "Wheat bran fibre contributes to an acceleration of intestinal transit" at 10 g a day and "Dried plums/prunes contribute to normal bowel function" at 100 g of dried plums a day.³ Our constipation guide has the NHS steps and the signs that need a GP rather than more fibre.

How do you get enough fibre on a low-carb diet?

UK food labels list fibre on its own line, outside the carbohydrate figure, so there is nothing to subtract; the trouble is that the pulses and wholegrains at the top of the table carry starch. The low-carb sources are seeds (6 to 12 g per 100 g for pumpkin, sunflower and sesame, linseed and chia far more), nuts, berries and larger portions of green and root vegetables; a day built on them reaches 15 to 20 g with effort and 30 g rarely, one reason low-carb eaters so often ask why they are constipated.²

Frequently asked questions

Are two wholewheat biscuits a day enough fibre?

Two biscuits of a wholewheat breakfast cereal give about 4 g, roughly an eighth of the adult target, so they are a start rather than the day's fibre; 80 g of raspberries (3.0 g) and a sliced pear (2.2 g) take the bowl to about 9 g.²

Which snack has the most fibre?

Per portion, 30 g of dried figs (3 g) or dates (2.3 g), 80 g of raspberries (3.0 g), 20 g of almonds (2.5 g) or a pear (2.2 g); oatcakes, rye crackers and hummus with vegetable sticks are the NHS's suggestions.^{1, 2}

Are eggs high in fibre, and is coffee a source of it?

Eggs, meat, fish, cheese, milk and yoghurt contain no fibre: fibre is the part of plant cell walls the small intestine cannot digest, plus starch that resists digestion.⁶ Brewed coffee carries 0.47 to 0.75 g of soluble fibre per 100 ml, roughly 1 to 2 g a mug.⁷

What is the best time of day to eat fibre?

Spread through the day. No trial shows an advantage for morning or evening; what matters is the total and the fluid taken with it.⁶

What is the healthiest grain to eat every day?

No single one. Oats bring beta-glucan, the gel-forming fibre with the cholesterol wording at 3 g a day; wholewheat and rye bring bran, the bulking fibre with the transit wording; barley brings both.^{3, 6}

Sources

1. NHS. How to get more fibre into your diet. nhs.uk.
2. Public Health England. McCance and Widdowson's Composition of Foods Integrated Dataset (CoFID), 2021. gov.uk. AOAC fibre column; portion values are calculated from it and rounded. Seed fibre, which CoFID does not give by this method, is from USDA FoodData Central (SR Legacy records 170556, 170562, 170150, 169414, 170554).
3. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. gov.uk.
4. Scientific Advisory Committee on Nutrition. Carbohydrates and Health, 2015. gov.uk; National Diet and Nutrition Survey 2019 to 2023. gov.uk.
5. Stacewicz-Sapuntzakis M, et al. Chemical composition and potential health effects of prunes: a functional food? Critical Reviews in Food Science and Nutrition, 2001. PubMed 11401245.
6. McRorie JW, McKeown NM. Understanding the physics of functional fibers in the gastrointestinal tract. Journal of the Academy of Nutrition and Dietetics, 2017. PubMed 27863994.
7. Díaz-Rubio ME, Saura-Calixto F. Dietary fiber in brewed coffee. Journal of Agricultural and Food Chemistry, 2007. PubMed 17295507.
8. Chey SW, et al. Exploratory comparative effectiveness trial of green kiwifruit, psyllium, or prunes in US patients with chronic constipation. American Journal of Gastroenterology, 2021. PubMed 34074830.
9. Attaluri A, et al. Randomised clinical trial: dried plums (prunes) vs. psyllium for constipation. Alimentary Pharmacology and Therapeutics, 2011. PubMed 21323688.

This article is general information, not medical advice. Increase fibre gradually with more fluid, and see a GP about a sudden change in bowel habit, blood in the stool or unexplained weight loss rather than changing your diet to manage it.