How Much Fibre Do You Need a Day? Targets, the Best Foods and How to Eat More

Most adults need about 25 to 38 grams of fibre a day: 25 g for women and 38 g for men aged 19 to 50, and about 21 g and 30 g after 50, according to the US National Academies. That works out at roughly 14 g for every 1,000 calories you eat. The UK recommends 30 g a day for all adults. Yet most people eat far less, often around half the target. This guide explains how much fibre you need, why it matters, which foods provide the most and how to eat more without digestive discomfort.

How Much Fibre Do You Need Per Day?

The most widely used US figures are the Adequate Intakes set by the National Academies of Sciences, Engineering, and Medicine (formerly the Institute of Medicine):

• Women 19 to 50: 25 g a day
• Men 19 to 50: 38 g a day
• Women 51 and over: 21 g a day
• Men 51 and over: 30 g a day
• Children: about 19 g at ages 1 to 3, rising to 25 g at 4 to 8, and higher in the teenage years

These targets are based on 14 g of fibre per 1,000 calories, the intake linked to a lower risk of heart disease in the studies the panel reviewed. The Dietary Guidelines for Americans 2020-2025 used the same benchmark, and the 2025-2030 edition, published in January 2026, continues to prioritise fibre-rich foods such as vegetables, fruit, beans and whole grains.

In the UK, the Scientific Advisory Committee on Nutrition recommends 30 g a day for adults, with 15 g for children aged 2 to 5, 20 g for ages 5 to 11 and 25 g for ages 11 to 16.

Are Most People Getting Enough Fibre?

No. Federal survey data suggest that American adults eat around 16 g a day on average, and an analysis published in the American Journal of Lifestyle Medicine estimated that more than 90% of women and 97% of men fall short of the recommendations. UK adults do a little better but still average only about 20 g a day, according to the National Diet and Nutrition Survey. US dietary guidance has long described fibre as a “nutrient of public health concern” because of how widespread the shortfall is.

Why Is Fibre Good for You?

Fibre is the part of plant foods that your body cannot fully digest. It comes in two main types, and most plant foods contain both:

• Soluble fibre, found in oats, barley, beans, lentils, apples and citrus fruit, forms a gel in the gut. It can help lower LDL (“bad”) cholesterol and slow the absorption of sugar.
• Insoluble fibre, found in wheat bran, whole grains, nuts and vegetable skins, adds bulk to stools and helps food move through the gut.

A major review commissioned by the World Health Organization and published in The Lancet in 2019 pooled 185 observational studies and 58 clinical trials. People who ate 25 to 29 g of fibre a day had a 15% to 30% lower risk of death from all causes and from heart disease, as well as lower rates of coronary heart disease, stroke, type 2 diabetes and bowel cancer, compared with people who ate the least. Higher intakes appeared to bring even greater benefits.

Fibre also feeds beneficial gut bacteria, helps prevent constipation and makes meals more filling, which can help with weight management.

Which Foods Are Highest in Fibre?

These approximate values come from the USDA’s FoodData Central database:

• Lentils, 1 cup (198 g) cooked: about 15 g
• Black beans or chickpeas, 1 cup cooked: about 12 to 15 g
• Chia seeds, 2 tablespoons (28 g): about 10 g
• Raspberries, 1 cup: about 8 g
• Green peas, 1 cup cooked: about 9 g
• Pear, 1 medium with skin: about 5.5 g
• Avocado, half: about 5 g
• Broccoli, 1 cup cooked: about 5 g
• Apple, 1 medium with skin: about 4.5 g
• Oats, half a cup (40 g) dry: about 4 g
• Baked potato with skin, 1 medium: about 4 g
• Almonds, 1 ounce (28 g): about 3.5 g
• Wholemeal bread, 1 slice: about 2 g

Beans, lentils and other pulses are the stand-outs, providing fibre, protein and minerals cheaply. Our guide on how much protein you need per day shows how they can help with both goals.

What Does a Day of 30 Grams of Fibre Look Like?

Reaching the target is easier than it sounds when you build each meal around plants:

• Breakfast: porridge made with 40 g of oats, topped with a cup of raspberries and a tablespoon of chia seeds (about 17 g)
• Lunch: a wholemeal sandwich with salad, plus an apple (about 8.5 g)
• Snack: a small handful of almonds (about 3.5 g)
• Dinner: a chickpea and vegetable curry with brown rice (about 10 g or more)

That simple day provides close to 40 g. Swapping white bread, rice and pasta for wholegrain versions, leaving the skins on fruit and vegetables, and adding a tin of beans to soups, stews and salads are the easiest everyday changes.

How Can You Increase Fibre Without Bloating?

A sudden jump in fibre can cause wind, bloating and cramps while your gut bacteria adjust. To avoid this:

• Increase gradually, adding a few grams a day over several weeks
• Drink enough fluid, because fibre absorbs water; our guide on how much water you should drink explains how much you need
• Spread fibre across the day rather than eating it all at once
• Cook pulses well, and rinse tinned beans to reduce some of the compounds that cause wind

If you have irritable bowel syndrome (IBS) or inflammatory bowel disease, some high-fibre foods may worsen symptoms. Ask your doctor or a registered dietitian for advice tailored to you.

Are Fibre Supplements as Good as Food?

Supplements such as psyllium husk can help with constipation, and psyllium has been shown to lower LDL cholesterol. But whole foods provide a mix of fibre types alongside vitamins, minerals and other plant compounds that supplements lack. Use supplements to fill gaps, not as a replacement for fruit, vegetables, pulses and whole grains, and check with a pharmacist if you take medicines, as fibre supplements can affect how some are absorbed.

Does Fibre Fit With Fasting or Low-Carb Diets?

It can, but it takes planning. Low-carb diets often cut grains, fruit and starchy vegetables, the main sources of fibre, so focus on non-starchy vegetables, nuts, seeds and avocado. If you follow time-restricted eating, a shorter eating window means fewer meals to fit fibre into; our guide to intermittent fasting for beginners covers how to plan balanced meals.

How Much Fibre per Day: Key Points

• Target: 25 g a day for women and 38 g for men aged 19 to 50 (US); 30 g for adults (UK)
• Rule of thumb: 14 g per 1,000 calories
• Best sources: beans, lentils, whole grains, fruit, vegetables, nuts and seeds
• Benefits: lower risk of heart disease, stroke, type 2 diabetes and bowel cancer
• How to increase: gradually, with plenty of water

This article is for general information and is not a substitute for personalised medical advice.

Featured image: Mixture of beans (small red, cannellini, pinto, roman, red kidney, black), peas (blackeye, yellow split), and pardina lentils 33, by Bean appreciator / Wikimedia Commons, released under CC0. Cropped, colour-graded and combined with MediaPavilion branding.

Sources

• National Academies of Sciences, Engineering, and Medicine — Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005).
• US Departments of Agriculture and Health and Human Services — Dietary Guidelines for Americans (accessed 1 November 2026).
• Reynolds A. et al., The Lancet — Carbohydrate quality and human health: a series of systematic reviews and meta-analyses (2019).
• Quagliani D. and Felt-Gunderson P., American Journal of Lifestyle Medicine — Closing America’s Fiber Intake Gap (2017).
• NHS — How to get more fibre into your diet (accessed 1 November 2026).
• Scientific Advisory Committee on Nutrition (GOV.UK) — Carbohydrates and Health report (2015).
• USDA Agricultural Research Service — FoodData Central (accessed 1 November 2026).