Fibre is one of the least glamorous parts of a healthy diet, but it may be one of the most useful when you are trying to lose weight. High-fibre foods tend to be filling, take longer to eat and digest, and come packaged with vitamins and minerals. Yet most people in the UK fall well short of the recommended amount.
This guide explains what fibre is, how it may help with weight loss, how much you need, and how to get more of it with everyday foods.
What is fibre?
Fibre is a type of carbohydrate found in plant foods that your body cannot fully digest. Instead of being absorbed like sugar or starch, it passes through your gut, where it helps keep your digestion moving. Some fibre is also fermented by the bacteria in your large intestine, which is thought to be good for gut health.
Fibre is found only in plant foods: wholegrains, fruit, vegetables, beans, lentils, nuts and seeds. Meat, fish, eggs and dairy contain none.
Soluble and insoluble fibre
You will often see fibre described as soluble or insoluble. The British Dietetic Association notes that soluble fibre (including pectins and beta-glucans) is found in foods like fruit and oats, while insoluble fibre (including cellulose) is found in wheat bran and nuts. It also explains that scientists increasingly describe fibre in more detail than these two groups, but they remain a useful starting point:
| Type | What it does | Good sources |
|---|---|---|
| Soluble fibre | Absorbs water and forms a gel-like texture in the gut | Oats, barley, beans, lentils, fruit such as apples and berries, root vegetables |
| Insoluble fibre | Adds bulk and helps food pass through the gut | Wholemeal bread, wholegrain cereals, brown rice, nuts, seeds, skins of fruit and vegetables |
Most plant foods contain a mixture of both, so the simplest approach is to eat a wide variety.
How much fibre do you need?
Government guidelines say adults should aim for 30g of fibre a day as part of a healthy balanced diet. This recommendation comes from the Scientific Advisory Committee on Nutrition (SACN) Carbohydrates and Health report. According to the NHS, most adults only eat an average of about 20g a day, so many of us need to find ways to increase our intake.
How fibre can help with weight loss
It helps you feel full
High-fibre foods tend to be bulky and low in energy density. Vegetables, fruit, pulses and wholegrains fill up your plate and your stomach for relatively few calories, and they usually take more chewing, which slows you down. Our guide to low-calorie foods explains this idea of energy density in more detail.
The evidence
A study by Miketinas and colleagues in the Journal of Nutrition analysed data from the POUNDS Lost trial, in which adults followed different calorie-restricted diets. Fibre intake was the most influential dietary predictor of weight loss, regardless of the proportions of fat, protein and carbohydrate in the diet. People who ate more fibre were also more likely to stick to their diet.
A large series of systematic reviews and meta-analyses published in The Lancet by Reynolds and colleagues found that clinical trials showed significantly lower body weight, blood pressure and total cholesterol with higher fibre intakes. In observational studies, people eating the most fibre had a 15–30% lower risk of death from all causes and from heart disease, as well as lower rates of stroke, type 2 diabetes and bowel cancer, compared with those eating the least. The benefits were greatest at intakes of around 25–29g a day.
The best high-fibre foods
Fibre content varies by brand and portion, so check food labels. The NHS explains that high-fibre foods have 6g or more of fibre in every 100g.
| Food group | Examples |
|---|---|
| Wholegrains | Porridge oats, wholewheat cereal biscuits, bran flakes, wholemeal or granary bread, brown rice, wholewheat pasta, bulgur wheat, barley, quinoa |
| Pulses | Lentils, chickpeas, kidney beans, black beans, baked beans, butter beans, split peas |
| Vegetables | Peas, sweetcorn, broccoli, carrots, Brussels sprouts, spinach, potatoes with skins |
| Fruit | Raspberries, blackberries, pears and apples with skin, oranges, bananas, dried fruit such as prunes (in small portions) |
| Nuts and seeds | Almonds, chia seeds, linseeds, pumpkin seeds (energy-dense, so keep portions small) |
Easy swaps to boost your fibre
| Instead of | Swap to |
|---|---|
| White bread | Wholemeal, granary or seeded bread |
| Sugary cereal | Porridge, bran flakes or wholewheat cereal biscuits |
| White rice or pasta | Brown rice or wholewheat pasta (or half and half to start) |
| Peeled potatoes | Potatoes boiled or baked with their skins on |
| Crisps | Plain popcorn, a handful of nuts or vegetable sticks with hummus |
| Fruit juice | A piece of whole fruit |
| Meat-only chilli or bolognese | Add lentils, beans or extra vegetables |
A sample high-fibre day
| Meal | Example |
|---|---|
| Breakfast | Porridge with raspberries and a tablespoon of chia seeds or linseeds |
| Lunch | Lentil and vegetable soup with a slice of wholemeal bread |
| Snack | A pear with the skin on, or carrot sticks with hummus |
| Dinner | Bean and vegetable chilli with brown rice and a side of greens |
| Pudding | Plain yoghurt with sliced apple and a sprinkle of oats |
Each of these meals includes a good source of fibre, and together they make reaching 30g much more achievable than relying on one "high-fibre" food. For extra fullness, pair them with protein. See our high-protein foods guide.
How to increase fibre comfortably
Adding a lot of fibre very quickly can leave some people feeling windy or bloated. These common-sense habits can help:
- Increase gradually over a few weeks so your gut can adjust.
- Drink plenty of fluids, especially water, as fibre needs fluid to work well.
- Spread it through the day rather than eating it all at one meal.
- Vary your sources: a mix of wholegrains, pulses, fruit and vegetables is better than relying on one food.
If you have a digestive condition such as irritable bowel syndrome (IBS) or inflammatory bowel disease, some high-fibre foods may make symptoms worse. Speak to your GP or a registered dietitian for tailored advice.
Frequently asked questions
Can fibre on its own make me lose weight?
No single food or nutrient causes weight loss by itself. But eating more fibre can help you feel fuller and make a lower-calorie diet easier to stick with, and research links higher fibre intakes with lower body weight.
Are fibre supplements as good as food?
Fibre from food comes with vitamins, minerals and other beneficial compounds, and food is the best way to meet your needs. Talk to a pharmacist, GP or dietitian before taking fibre supplements, especially if you take medication.
Is brown bread the same as wholemeal?
Not always. Some brown bread is made with refined flour and colouring. Look for "wholemeal" or "wholegrain" in the ingredients.
Why do beans make me bloated?
Beans contain fibre that is fermented by gut bacteria, which can produce gas. Starting with small portions, rinsing tinned beans and increasing slowly usually helps.
What is the easiest way to get more fibre?
Switching to a higher-fibre breakfast, such as porridge or wholegrain cereal with fruit, and adding a portion of pulses or extra vegetables to your main meal can make a big difference.
Related guides
- High-protein foods and diet for weight loss
- Low-calorie foods and snacks
- The Mediterranean diet for weight loss
- Healthy snacks for weight loss
Sources
- NHS: How to get more fibre into your diet https://www.nhs.uk/live-well/eat-well/digestive-health/how-to-get-more-fibre-into-your-diet/
- British Dietetic Association (BDA): Fibre food fact sheet https://www.bda.uk.com/resource/fibre.html
- Scientific Advisory Committee on Nutrition (SACN): Carbohydrates and Health report (GOV.UK) https://www.gov.uk/government/publications/sacn-carbohydrates-and-health-report
- Miketinas DC et al. (2019). Fiber intake predicts weight loss and dietary adherence in adults consuming calorie-restricted diets: the POUNDS Lost study. Journal of Nutrition. https://pubmed.ncbi.nlm.nih.gov/31174214/
- Reynolds A et al. (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet. https://pubmed.ncbi.nlm.nih.gov/30638909/
- NHS: Starchy foods and carbohydrates https://www.nhs.uk/live-well/eat-well/food-types/starchy-foods-and-carbohydrates/
- NHS: Food labels https://www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/how-to-read-food-labels/
Medical disclaimer: this guide is general information only, not medical advice. Speak to your GP or a registered dietitian before making major changes to your diet, especially if you have a health condition, are pregnant or take medication. See our Medical Disclaimer.