Why Fibre Matters (and How to Get Enough)

Fibre rarely gets star billing in the way that protein or vitamins do, yet it is one of the most valuable parts of a healthy diet — and one that most people in the UK simply do not get enough of. Often dismissed as merely "roughage" for keeping you regular, fibre actually does a remarkable amount of work for your health. This guide explains what fibre is, the two main types, the best sources, the benefits, and how to get more without discomfort. This is general information, not medical advice.

What it is

Dietary fibre is a type of carbohydrate found in plant foods that the body cannot fully digest and absorb. Unlike sugars and starches, which are broken down for energy, fibre largely passes through the digestive system intact — and that is precisely the point. Its value lies in what it does on the way through.

Because it is not fully digested, fibre adds bulk, slows certain processes, and feeds the helpful bacteria living in your gut. You will only find it in plants: vegetables, fruit, wholegrains, beans, pulses, nuts and seeds. Animal foods such as meat, fish, eggs and dairy contain no fibre at all, which is one reason a plant-rich diet tends to be a higher-fibre one.

Soluble versus insoluble fibre

Fibre is not a single substance. It is usually divided into two main types, and most plant foods contain a mixture of both.

• Soluble fibre dissolves in water to form a soft, gel-like substance in the gut. This gel slows digestion, which can help steady the rise in blood sugar after eating and can help lower blood cholesterol. Good sources include oats, barley, beans, lentils, apples, citrus fruit and many vegetables.
• Insoluble fibre does not dissolve in water. Instead it adds bulk to the contents of the gut and helps everything move through more smoothly, supporting regularity and helping to prevent constipation. Good sources include wholemeal bread, brown rice, wholegrain cereals, nuts, seeds and the skins of fruit and vegetables.

In practice you do not need to track the two types separately. Eating a variety of plant foods naturally gives you a good balance of both.

The benefits

The case for fibre has grown steadily as research has accumulated, and it now extends well beyond digestion. A higher-fibre diet is associated with a range of benefits, which is why health bodies such as the NHS and the British Nutrition Foundation encourage people to eat more.

• Better digestion and regularity. Fibre, especially the insoluble kind, keeps the digestive system moving and helps prevent constipation.
• Gut health. Some fibres act as food for beneficial gut bacteria, supporting a healthy gut microbiome.
• Heart health. Soluble fibre can help lower cholesterol, and higher-fibre diets are linked to a reduced risk of cardiovascular disease.
• Steadier blood sugar. By slowing digestion, fibre can help moderate blood sugar rises, which is relevant to managing and reducing the risk of type 2 diabetes.
• Feeling fuller. High-fibre foods tend to be more filling and slower to eat, which can support appetite control and a healthy weight.
• Lower risk of some conditions. Diets rich in fibre are associated with a lower risk of certain bowel conditions, including bowel cancer.

Fibre is one of the clearest examples of food doing more than feeding you. The same humble bowl of oats or plate of beans is quietly working on your heart, your gut and your blood sugar at once.

These benefits come from whole foods eaten regularly over time, not from a single "superfood" or a fibre supplement bolted onto an otherwise poor diet.

How much, and why most of us fall short

UK government advice recommends that adults aim for around 30 grams of fibre a day. The reality is that most people eat considerably less — surveys suggest the average UK adult gets nearer 20 grams, well short of the target. Children need less than adults, with amounts rising as they grow.

Part of the reason for the shortfall is the modern diet's reliance on refined and processed foods, where much of the fibre has been removed. White bread, white rice and many packaged snacks contain far less fibre than their wholegrain equivalents. Closing the gap is mostly about swapping refined foods for less-processed ones and eating more plants.

How to get enough

The good news is that boosting your fibre intake is straightforward and need not be unpleasant. Practical steps include:

• Choose wholegrains over refined versions: wholemeal bread, brown rice, wholewheat pasta and wholegrain breakfast cereals.
• Leave the skins on fruit and vegetables where you can, since much of the fibre is in or near the skin.
• Add beans, lentils and pulses to soups, stews, salads and curries — they are among the richest fibre sources.
• Snack on nuts, seeds and fruit rather than refined snacks.
• Eat plenty of vegetables with meals, aiming for variety and colour.
• Start the day with oats or a wholegrain cereal.

Two cautions are worth heeding. First, increase fibre gradually rather than all at once; a sudden jump can cause bloating and wind while your gut adjusts. Second, drink enough fluid, because fibre works best with plenty of water. Building these habits fits naturally into the wider principles of a balanced diet and sensible portion sizes, and it pairs well with understanding the vitamins and minerals that plant foods also provide.

The bottom line

Fibre is the part of plant foods your body cannot fully digest, and it earns its place in a healthy diet many times over — supporting digestion and gut health, helping your heart and blood sugar, and keeping you feeling full. There are two main types, soluble and insoluble, and a varied, plant-rich diet supplies both. UK adults should aim for around 30 grams a day, yet most of us fall short, largely because of refined and processed foods. Build up gradually, drink plenty of water, and reach for wholegrains, beans, fruit, vegetables, nuts and seeds. It is one of the simplest and most worthwhile changes you can make to how you eat.