How much fibre do you need? Many of us fall short

Ask most people how much fibre they eat in a day, and they'll shrug. It's not a nutrient we tend to think about in the context of a balanced diet the same way we think about protein or sugar. But it turns out that gap in awareness matches a much bigger gap on our plates.

Data from the National Diet and Nutrition Survey shows that only around 4 in 100 UK adults hit the recommended 30g of fibre a day. The average intake sits closer to 16g, which is roughly half of what we need. No age group in the UK currently meets the target, something that's been true for years, so not just a recent dip.

In clinic, fibre is one of the first things I look at with almost every client, regardless of what's actually brought them through the door. It's rarely the headline complaint; nobody books a call and says "I think my fibre's low", but it's often sitting underneath digestive issues, energy crashes, skin flare-ups and hormonal symptoms that seem, on the surface, unrelated to each other. Few single dietary changes have that much reach.

Here's what fibre is actually doing in the body, why so many of us fall short without realising it, and how to close the gap without turning your diet upside down.

What fibre is doing behind the scenes

Fibre is the part of plant food your body can't fully break down, but can't digest doesn't mean it doesn't matter. If anything, it's the opposite.

Once fibre reaches your large intestine, it becomes food for the trillions of bacteria living there. A well-fed, diverse gut microbiome is linked to smoother digestion, stronger immune function, regulated hormones, and even mood, since a substantial share of your serotonin is produced in the gut rather than the brain.

Soluble fibre in particular binds to cholesterol in the digestive tract and helps carry it out of the body, which is a large part of why higher fibre intake is consistently associated with better cardiovascular outcomes. Fibre also slows down how quickly sugar enters your bloodstream, which means steadier energy, fewer cravings, and an easier time managing weight without needing to restrict.

There's a hormonal piece too, one that comes up a lot with clients dealing with oestrogen-related symptoms. Fibre helps bind to excess oestrogen in the digestive tract so it can be cleared from the body, rather than being reabsorbed and recirculated. And research continues to build a case for fibre's role in cognitive health via the gut-brain axis, alongside its links to blood pressure, glucose control, and lower chronic inflammation.

Put simply: whatever brought you to think about your diet, digestion, energy, skin, hormones, or heart health, fibre is quietly involved in most of it.

Why we're all falling short

If fibre is doing this much, why are 96% of us under-eating it? In my experience, it's almost never down to someone not trying. It's much more to do with how the modern UK diet is structured.

A large share of what most people eat day to day is ultra-processed, and these foods are typically stripped of fibre during manufacturing to extend shelf life and improve texture. On top of that, most of us eat a fairly narrow rotation of the same handful of fruits, vegetables and grains, week after week, and gut bacteria thrive on variety, not just volume. You can be eating enough plants and still be missing out if they're always the same ones.

Then there's the default choice at most meals: white bread, white rice, white pasta. They're familiar, convenient and often cheaper, but refining strips out much of the fibre-rich outer layer of the grain in the process.

None of this comes down to willpower. It's the food environment most of us are working with.

Signs your fibre intake might be low

A few patterns tend to point toward low fibre intake, although they can have other causes too, so none of them is diagnostic on their own:

• bloating or a stomach that feels unpredictable
• constipation or irregular bowel movements
• cholesterol that's crept up at a check-up despite feeling like you eat reasonably well
• blood sugar that seems to spike then crash after meals
• energy dips a couple of hours after eating
• feeling hungry again soon after a meal
• skin that's more reactive or breakout-prone than expected
• hormonal symptoms that feel harder to pin down
• craving something sweet after meals, or reaching for refined snacks mid-afternoon
• weight that's crept up gradually without an obvious change in what you eat

If several of these sound familiar, fibre is a reasonable place to start looking, though it's rarely the whole picture on its own, which is usually where working with someone helps.

What 30g actually looks like on a plate

Thirty grams sounds like a lot until you break it down across a day:

• porridge with berries, a spoon of chia seeds and some flaked almonds
• a salad with lentils and roasted vegetables, rocket, feta and olive oil
• a handful of walnuts or edamame as a snack
• brown rice or quinoa in place of white rice at dinner
• a beef chilli loaded with kidney beans, topped with avocado, coriander and spring onion

None of that is 'diet' food. It's just an ordinary day of eating that happens to be doing a lot of quiet work in the background.

Building it up without overhauling everything

You don't need to fix this overnight, and I don't believe you should try to. A sudden jump in fibre intake is one of the more common causes of the exact bloating and discomfort people are trying to avoid in the first place. The better approach is gradual, alongside plenty of water, since fibre needs fluid to do its job properly.

A few starting points that tend to work well:

• Swap one white carbohydrate a day for a higher-fibre version: brown rice, 100% rye bread, red lentil pasta, or quinoa instead of couscous.
• Add whole seeds, milled seeds, or nuts to porridge, overnight oats, yoghurt or smoothies.
• Add a tin of beans or lentils to something you already cook, like a bolognese or curry.
• Leave the skin on fruits and veg rather than peeling them.
• Try to get two different plant foods on your plate at every meal, not just at dinner.
• Build it up over several weeks rather than all at once; your gut will thank you for the patience.
• Don't let your salad be all leaves; they are surprisingly low in fibre. Level them up by adding chickpeas, lentils, wholegrains, nuts, seeds, avocado, artichoke, broccoli or peas.

The bottom line

Fibre isn't a wellness trend. It's one of the most well-evidenced, far-reaching nutrients in the average diet, and one of the easiest to under-eat without ever realising it. Given that 96% of UK adults are falling short, there's a good chance you are too, even if you already think of yourself as eating well.

The encouraging part is that fibre is genuinely one of the more fixable areas of nutrition. Small, consistent changes add up faster than most people expect, and you don't need to get everything right straight away.

If several of the signs above sound familiar, it's worth having a proper look at where the gaps are. A registered nutritional therapist can help you work out what's actually going on and build a realistic plan around it, rather than guessing your way through another round of diet swaps.