Adults in the UK are advised to eat at least 30g of fibre a day, and almost everyone falls short. This article covers what the latest national survey found, what the evidence says fibre does, and how an ordinary day of food can add up to the target.
What does the 30g target actually mean?
The recommendation is at least 30g of fibre a day for adults. Children’s figures are lower and rise with age: about 15g a day for two to five-year-olds, about 20g for five to 11-year-olds and about 25g for 11 to 16-year-olds, according to the NHS.
Fibre is the part of plant foods that the body does not fully digest. It is found in fruit, vegetables, pulses, nuts, seeds and wholegrain cereals. The British Dietetic Association describes two broad types: soluble fibre, found in foods such as fruit and oats, and insoluble fibre, found in wheat bran and nuts. Most plant foods contain a mixture, so there is no need to track the types separately.
How far short are UK adults?
The National Diet and Nutrition Survey, covering 2019 to 2023 and published on GOV.UK, found that 96% of adults did not meet the fibre recommendation, which means only about 4% did. Average daily intake was 16.4g for adults aged 19 to 64, 16.9g for those aged 65 to 74 and 16.4g for those aged 75 and over.
Other sources quote slightly different averages, such as roughly 18g from the British Dietetic Association and about 20g from the NHS. That is because they draw on different survey years and methods. The consistent message is that typical intake is well below the target, at somewhere around half to two-thirds of it.
The survey authors also note that people tend to under-report how much they eat, so the figures are best read as a broad picture and not as precise measurements.
Where does the fibre in a typical diet come from?
Cereals and cereal products were the main source for every age group in the survey, providing 43% to 50% of average daily fibre. Vegetables and vegetable dishes came second at 19% to 25%, and fruit supplied 6% to 12% for adults.
This matters because it shows where small swaps count for most. If bread, breakfast cereal and pasta provide nearly half of your fibre, then the type you choose has an outsized effect. Wholemeal, granary and wholewheat versions carry far more than refined white ones.
What does the evidence say fibre does for health?
The NHS states that eating plenty of fibre is associated with a lower risk of heart disease, stroke, type 2 diabetes and bowel cancer. The word “associated” is important. Much of the evidence comes from large observational studies, which compare people who eat more fibre with those who eat less. Those groups also tend to differ in other ways, such as smoking, activity and the rest of their diet, so the studies cannot prove that fibre itself is responsible.
What can be said with reasonable confidence is that fibre helps keep bowel movements regular, and that high-fibre diets tend to be built from foods that are filling and nutritious. Fibre should not be thought of as a treatment for any disease. It is one feature of a generally balanced pattern of eating, which our guide to what a balanced everyday diet looks like covers in more detail.
How do you read a label for fibre?
Labels are the quickest way to compare products. The British Dietetic Association explains the standard guide:
| Per 100g | What it means |
|---|---|
| 3g or more | A source of fibre |
| 6g or more | High in fibre |
The same fact sheet gives examples of total fibre per 100g, including shredded whole wheat or bran cereals at 13 to 24.5g, almonds at 7.4g, peanuts at 7.6g, figs at 6.9g, boiled peas at 5.6g, baked beans in tomato sauce at 4.9g, strawberries at 3.8g and boiled broccoli at 2.8g. Remember that these are per 100g. A typical portion of broccoli or strawberries is not 100g, and a serving of cereal is usually smaller than that too, so check the portion you actually eat.
What does a 30g day look like in practice?
The NHS gives an example day that reaches the target without any specialist ingredients. The figures are approximate, and fibre content varies with preparation and portion size.
- Breakfast: two slices of wholemeal toast with peanut butter and a medium orange, about 8.3g
- Lunch: wholemeal spaghetti with a lentil and tomato sauce, about 11g
- Dinner: grilled chicken breast, a baked potato with the skin on, carrots and green beans, about 11.2g
Illustrative arithmetic: 8.3g + 11g + 11.2g = 30.5g, which clears the 30g mark before any snacks. Fruit, unsalted nuts, oatcakes, vegetable sticks or crackers with hummus would add more.
The pattern behind the example is simple: wholegrain versions of the starchy staples, pulses in at least one meal, vegetables with lunch and dinner, and the skin left on where it is edible.
Which swaps are easiest to make?
The NHS suggests a handful of changes that do not require a new way of eating:
- Choose higher-fibre breakfast cereals such as plain wholewheat biscuits, plain shredded wholegrain or porridge.
- Pick wholemeal or granary bread, or a higher-fibre white loaf.
- Swap to wholewheat pasta, bulgur wheat or brown rice.
- Eat potatoes with their skins on.
- Add beans, lentils or chickpeas to stews, curries and salads.
- Snack on fresh fruit, vegetable sticks, oatcakes or unsalted nuts and seeds.
Tinned and frozen options count too, which helps with cost. The NHS also notes that dried fruit is best eaten with meals, because it is sticky and can raise the risk of tooth decay. Highly processed products marketed as “high fibre” are not automatically a better choice than whole foods, a point explored in our look at ultra-processed foods and the evidence.
Should you worry about bloating when you eat more fibre?
Many people do notice more wind or bloating if they raise their intake quickly. The British Dietetic Association advises increasing fibre gradually, to avoid symptoms such as bloating and gas and to let the gut adjust. It also notes that fibre draws water into the bowel, so you can become dehydrated if you do not drink enough, and that you should drink plenty of fluid as intake rises.
A sensible approach is to change one meal at a time over a few weeks, and to vary the sources rather than relying heavily on one food. The NHS makes the same point about variety.
People with irritable bowel syndrome may find that larger amounts of fermentable fibre cause bloating, gas and diarrhoea, and the dietetic advice is that guidance should be adapted to their medical history and tolerance. If that sounds familiar, a GP or a registered dietitian can help you find an approach that suits you.
When should you speak to a GP or NHS 111?
Fibre is not a cure for bowel problems, and some symptoms need checking rather than a dietary fix. The NHS advises seeing a GP if you:
- have constipation that is not getting better with treatment, or are regularly constipated or regularly bloated
- notice blood in your poo
- have lost weight without trying
- feel tired all the time alongside constipation
- have sudden changes in your bowel habits
- have tummy pain
- take a medicine, such as an opioid painkiller, that is causing constipation
Speak to the GP before you stop taking any prescribed medicine. If you are unsure how urgent a symptom is, NHS 111 can advise.
Closing thoughts: small, repeatable changes beat a perfect plan
The gap between 16g and 30g can sound large, but it is mostly closed by a few repeated habits: a wholegrain breakfast, pulses a few times a week, vegetables at two meals and fruit or nuts as snacks. Protein and fibre often arrive together in beans and lentils, so these foods also help with the questions raised in our guide to how much protein you need. Build up slowly, drink enough fluid, and treat any persistent or worrying change in your bowels as a reason to see a professional.
This is general information, not a substitute for advice from a doctor or other qualified health professional. If you are worried about your digestion or any symptoms, speak to your GP or call NHS 111.
Sources: NHS; GOV.UK; British Dietetic Association
