Fibre

You’ve probably heard that eating more fibre is good for you, but did you know that most of us don’t eat enough of it? Eating a wide variety of plant foods can boost your fibre intake and help you reap the benefits.

What is fibre?

Fibre is a type of carbohydrate and comes from plants. Unlike other carbohydrates (sugar and starch), it is not digested and absorbed in the small intestines. Instead, it passes undigested into the large bowel where it’s completely or partially broken down by the bacteria that naturally live there.

What are the types of fibre?

You may have heard of the terms ‘soluble fibre’ and ‘insoluble fibre’. These words are often used to describe the different types of fibre in our diets.

Soluble fibre absorbs water in the gut. It’s found in:

• oats
• barley
• pulses (such as beans, peas and lentils)
• some fruits and vegetables. 

Insoluble fibres are not soluble in water. They are mainly found in:

• wholegrains, especially the bran part of the grain
• vegetables
• the seeds and skin of fruits.

The terms 'soluble' and 'insoluble' have fallen out of favour recently because there are other qualities of fibre which are now known to be important. Such as, whether the soluble fibre forms a gel in the gut or if a fibre is fermentable, which means it can be broken down by gut bacteria.

For good health, aim to eat more fibre from a variety of foods, such as:

• pulses (peas, beans and lentils)
• fruits
• vegetables
• wholegrains
• nuts and seeds. 

A lot of this fibre will also be fermentable, meaning that the friendly bacteria in your large bowel will break it down and produce many by-products that are good for your health.

Why is fibre good for your heart?

As well as keeping your gut healthy, eating more fibre has been linked to a lower risk of heart disease, Type 2 diabetes and obesity.

Studies have found that people who eat more fibre have a lower body weight, lower blood pressure and lower cholesterol – which is great for your heart health. There are a number of possible reasons for these effects.

• Fibre can help you to feel full, which helps prevent overeating. This can help you maintain a healthy weight, which is good for blood pressure, blood sugar control and cholesterol management.
• Certain soluble fibres form a gel-like substance in the gut. This includes the fibre in oats, barley and pulses. It helps delay or reduce certain nutrients from being absorbed into your blood, such as sugar and fats including cholesterol.
• Some types of fibre provide food for ‘friendly’ gut bacteria. This encourages the bacteria to thrive and produce substances which are thought to be protective for heart health. These can have a number of benefits such as helping to lower cholesterol.

Fibre may also be a marker for an overall healthy diet. If your diet contains a lot of fibre, it’s likely that you’re eating lots of plant foods which contain other important nutrients for heart health, such as vitamins, minerals, antioxidants and plant compounds.

A special word about oat and barley fibre

Oats and barley contain a special form of soluble fibre called beta glucan which, as part of a healthy diet, has been shown to lower cholesterol. Beta glucan works by forming a gel in the gut which can bind with cholesterol-rich bile acids and stop them being absorbed into the body.

You need 3g of beta glucan a day to help actively lower cholesterol. You can get this by eating 3 servings of the foods below, in any combination. 

Eat three servings of these foods each day 

• A bowl of porridge (using 30g of porridge oats)
• 13g (1-2 tablespoons) of oatbran – sprinkled onto cereals, or added to casseroles, soups or smoothies
• 250ml of oat drink (containing at least 1g of beta glucan per serving)
• 1 oat breakfast biscuit
• 1 serving of oat breakfast cereal flakes (30-35g)
• 3 oatcakes
• Recipes providing at least 30g of oats per serving that are also low in saturated fat
• 75g cooked pearl barley – you can add these to stews, casseroles, salads or use them instead of rice to make a risotto
• 40g of barley flakes

How much fibre should I be eating?

The recommended amount of fibre in the UK is 30g a day for adults, but most of us don’t eat this much.

The table below gives you an idea of how much fibre is in everyday foods.

Type of food	Foods	Typical portion size	Fibre content*
Starchy foods	Bran Flakes Wheat biscuit breakfast cereals Oats Wholemeal bread Wholewheat spaghetti  Brown Rice Barley Quinoa Baked potato with skin on	40g 2 30g 2 medium slices 75g raw 75g raw 25g raw 30g raw medium	5.4g 3.9g 2.3g 5.2g 8.8g 3.8g 3.1g 2.1g 4.3g
Fruits and vegetables	Apple  Banana Strawberries  Dried raisins  Dried apricots  Prunes Broccoli  Carrots	medium medium 80g 30g 30g 30g 80g, steamed 80g, boiled	2.1g 1.4g 3.0g 1.8g 6.5g 1.7g 2.2g 2.2g
Lentils, beans and peas	Peas Baked beans Kidney beans  Red lentils  Chickpeas	80g, cooked 200g 100g, cooked 100g, cooked 100g, cooked	4.4g 9.8g 8.5g 4.1g 4.8g
Nuts and seeds	Unsalted peanuts  Peanut butter Almonds  Walnuts  Sunflower seeds  Chia seeds  Linseeds	a handful, 30g 1 tbsp a handful, 30g a handful, 30g 25g 1 tbsp 1 tbsp	2.2g 1.4g 4.8g 1.8g 1.8g 3.9g 2.6g

* These are approximate amounts which may differ between brands.

How to boost your fibre intake

1. Start the day with a high fibre breakfast cereal. Add some fresh fruit, dried fruit, seeds or nuts to add extra fibre.
2. Go for wholemeal or seeded wholegrain breads.
3. For snacks, try fruit, vegetable sticks with hummus, rye crackers, oatcakes or unsalted nuts.
4. Choose wholegrains like wholewheat pasta, quinoa or brown rice.
5. Go for potatoes with skins left on. Such as baked potato, wedges or boiled new potatoes. These can be eaten hot or used cold for a salad.
6. Swap some meat for plant proteins. Beans, lentils, soy foods, nuts and seeds all contain fibre along with protein and heart-healthy fats.
7. Add pulses or barley to homemade soups.
8. Mix seeds into yoghurts, and sprinkle them on top of salads.
9. Eat plenty of vegetables with your meals. Ether as a side dish or side salad, or added to sauces, stews or curries.

Gradually build up how much fibre you eat

Eating too much too soon may make you feel uncomfortable. It’s also a good idea to drink more water when you start eating more fibre.