Fibre has had a remarkable year. Search interest in "fibremaxxing" and gut health has climbed across the UK, supermarkets are filling shelves with high-fibre breads and snacks, and plenty of people who used to count only protein are now counting grams of fibre too. That is good news, because most of us still fall well short of the UK recommendation. This guide explains what fibre actually does, how active people can hit their target without an upset stomach, and where (if anywhere) supplements fit in.
How much fibre do UK adults need?
The UK government recommends that adults eat 30 g of fibre a day. National diet survey data consistently shows that the average adult manages only around 18–20 g, so most of us have a gap of roughly 10 g every single day. Children need less (around 15 g for ages 2–5, rising to 25 g for 11–16 year olds), but the same pattern applies: very few reach it.
Closing that gap does not require anything exotic. A bowl of porridge, a portion of beans or lentils, two pieces of fruit and a couple of extra portions of vegetables can add 15 g or more to a typical day.
What fibre does in your body
"Fibre" is not one thing. It is a family of plant carbohydrates that your own digestive enzymes cannot fully break down, so they travel further along the gut than sugars and starches do. Broadly, there are two types:
- Soluble fibre – found in oats, barley, beans, lentils, apples and citrus fruit. It absorbs water and forms a gel.
- Insoluble fibre – found in wholegrain bread, bran, nuts, seeds and the skins of fruit and vegetables. It adds bulk.
Some fibres also have authorised health claims in Great Britain when eaten in the right amounts. For example, oat grain fibre contributes to an increase in faecal bulk, and wheat bran fibre contributes to an acceleration of intestinal transit. Those are food facts, and they are a good reason to build meals around whole grains rather than refined ones.
Many fibres are also fermented by the bacteria that live in the large intestine. This is the part of the story that has fuelled the gut-health boom. Research into the gut microbiome is exciting, but it is still young, and much of what you see online goes far beyond the evidence. The most reliable advice remains the simplest: eat a wide variety of plant foods.
The "30 plants a week" idea
A popular way to think about variety is to aim for 30 different plant foods a week. Fruit, vegetables, whole grains, beans, nuts, seeds, herbs and spices all count. It is not an official target, but it is a useful game: rather than eating the same broccoli and rice every day, you rotate. A bag of mixed seeds, a tin of mixed beans and a handful of frozen berries can add five or six "plants" in one go.
Fibre for people who train
Active people often have a particular problem with fibre: timing. A large, fibre-rich meal right before a run or a heavy leg session can leave you feeling heavy or send you looking for the nearest toilet. A few practical rules help:
- Front-load fibre away from training. Have your high-fibre meals two to three hours or more before a session, or after it.
- Keep pre-workout snacks lower in fibre. A banana, white toast with honey or a rice cake is easier to digest close to exercise.
- Increase slowly. Jumping from 15 g to 40 g overnight is a recipe for wind and bloating. Add about 5 g a week until you reach your target.
- Drink more water. Fibre works best with plenty of fluid, especially soluble fibre.
- Do not forget protein. High-fibre eating and high-protein eating are not in competition. Beans, lentils, edamame and oats bring both.
A sample 30 g day
| Meal | Example | Approx. fibre |
|---|---|---|
| Breakfast | Porridge (50 g oats) with raspberries and a spoon of chia seeds | 9 g |
| Lunch | Wholemeal wrap with chicken, hummus and salad | 7 g |
| Snack | An apple and a small handful of almonds | 5 g |
| Dinner | Chilli with kidney beans, brown rice and peppers | 11 g |
| Total | ≈32 g |
Figures are approximate and vary by brand and portion, but the point stands: you can reach 30 g with normal, enjoyable food.
Where do gut-focused supplements fit?
Food comes first, and no capsule can replace a diet rich in plants. That said, some people like to add a supplement to their routine, particularly when their diet is less varied than they would like, for example during travel or busy periods.
It is worth being clear about what the law allows here. In Great Britain there are currently no authorised health claims for live bacterial cultures, so any brand that promises that a product will "fix" your gut, boost immunity or cure bloating is going beyond the rules. What we can tell you is what a product contains. Our live-culture supplement combines bacterial cultures with inulin, a fibre found naturally in foods such as chicory root, onions and leeks.
Live bacterial cultures combined with inulin, a type of fibre, in gastro-resistant capsules.
View product →Digestive enzyme supplements are another category people ask about, especially those eating large high-protein meals. Your body already produces its own digestive enzymes, and calcium contributes to the normal function of digestive enzymes, so a diet with enough calcium-rich foods matters. Enzyme supplements are not a substitute for that, and again there are no authorised claims for them, but some people choose to include them alongside their meals.
Common fibre mistakes
- Relying on one "super" food. Chia seeds are great, but variety matters more than any single ingredient.
- Swapping meals for fibre powders. Isolated fibres can be useful, but whole foods bring vitamins, minerals and other plant compounds too.
- Ignoring symptoms. Ongoing changes in bowel habits, persistent pain, blood or unexplained weight loss are reasons to see your GP, not to try a new supplement.
Products mentioned in this article
Live bacterial cultures combined with inulin, a type of fibre, in gastro-resistant capsules.
View product →
A capsule combining the DigeZyme® multi-enzyme blend with clove extract, taken with meals.
View product →FAQs
How much fibre should I eat a day in the UK?
The UK recommendation for adults is 30 g a day. Most adults eat around 18–20 g, so increasing gradually by about 5 g a week is a sensible approach.
Is fibremaxxing safe?
Eating more fibre is a positive goal for most people, but going to extremes, or increasing intake too quickly, can cause wind, bloating and discomfort. Aim to reach the 30 g target gradually and drink plenty of fluids. If you have a digestive condition, speak to your GP or a dietitian first.
Should I eat fibre before training?
Large, high-fibre meals are best eaten two to three hours or more before exercise, or afterwards. Closer to a session, choose lower-fibre carbohydrate snacks that are easier to digest.
Can a supplement replace fibre-rich foods?
No. Supplements can sit alongside a good diet, but they cannot replace the range of fibres, vitamins and minerals found in whole grains, fruit, vegetables, beans, nuts and seeds.
Do live-culture supplements have proven health claims?
In Great Britain there are no authorised health claims for live bacterial cultures at the moment, so be cautious of any product that promises specific health effects.
Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle.