Fibre – are you getting enough?

| 4 August 2020
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There are three different types of carbohydrates found in food – sugar, starch and fibre. Fibre is the name for the large group of complex carbohydrates that we cannot digest and even though we don’t digest it, fibre is a very important and beneficial part of our diet. It keeps our digestive system healthy, encourages ‘good’ gut bacteria, improves our energy metabolism by slowing down sugar absorption and helps in healthy weight management. It can reduce high cholesterol and the risk of heart disease and stroke and lowers the risk of some cancers, particularly bowel cancer, and diabetes.


Are we getting enough?

In 2015, the government increased the recommended daily amount of fibre from 18 grams a day to 30 grams. Generally, we consume much less than that. In 2018, the UK National Diet and Nutrition Survey found that the average intake in adults was 19 grams per day, well below the recommended amount.

Children under the age of 16 don’t need as much fibre as older teenagers and adults but they still need more than they are currently getting:

  • 2-5 year-olds need about 15g of fibre a day
  • 5-11 year-olds need about 20g
  • 11-16 year-olds need about 25g

On average, children and teenagers are only getting around 15g or less of fibre a day.

There are two types of fibre.

Soluble fibre is normally a soft, moist fibre – the type found in fruit (but not the skins), vegetables and pulses such as peas, beans and lentils. It dissolves in water to form a gel, which can make you feel fuller for longer after a meal and makes stools soft and easier to pass. It is sometimes called a ‘prebiotic’ – food that feeds the friendly probiotic bacteria that inhabit your gut. They ferment it to produce health-promoting compounds, such as the short-chain fatty acid propionate which have cholesterol-lowering, anti-cancer and anti-inflammatory properties, as well as reducing fat storage. The best sources are wholegrains, fruit, pulses and root vegetables.

Insoluble fibre is mainly the outer shell of seeds, grains, fruits and vegetables – a tougher, less digestible fibre, it can be stringy or coarse and does not dissolve but absorbs water, increasing the stool bulk and helping to keep you ‘regular’. Insoluble fibre is essential for your digestive system to work properly and can help prevent and treat constipation, diverticulitis and irritable bowel syndrome (IBS). Other benefits come from it being partially fermented by gut bacteria. The best sources are wholegrain foods, breakfast cereals, unpeeled fruit and dried fruits, vegetables, nuts and seeds.


Which foods are best?

Fibre is found naturally in unrefined plant foods such as fruit and vegetables, wholegrains, pulses, nuts and seeds, but never in animal foods – meat and milk contain none. A varied vegan diet, containing the foods above, will contain plenty of both types of fibre. They will increase longevity, lower the risk of many diseases, including cancer, diabetes and heart disease, and help maintain healthy weight.

The claim that a food is high in fibre may only be made if it contains at least six grams of fibre per 100 grams of food.

Getting plenty of fibre in your diet is easy, without having to splash out on expensive or fancy foods. Include plenty of fruit and vegetables such as potatoes, sweet potatoes, carrots, sweetcorn, beetroot, broccoli, spring greens, cabbage, apples, bananas, oranges, strawberries and raspberries – they’re all great sources. Aim for at least five portions a day but preferably more.

Choose wholegrain foods such as wholemeal bread, brown rice, wholewheat pasta, high-fibre breakfast cereals and oats; avoid white bread and pasta as these contain less fibre. Pulses such as peas, chickpeas, kidney beans and lentils are all great sources so add them to soups, stews, salads and pasta dishes.

Nuts and seeds such as almonds, pecans and walnuts, provide plenty of fibre, as do sesame and sunflower seeds. Swap processed snacks for oatcakes, vegetables sticks and fruit – dried fruit is a good option. A small handful of unsalted nuts can provide up to three grams of fibre.

There are many ways to tweak your normal meals to boost the fibre content. If you start the day with cereal or muesli, try adding a sliced banana, a handful of berries or chopped nuts. If you are a homemade smoothie fan, add a small handful of almonds or a spoonful of ground flaxseed. Improve the old favourite of beans on toast by using wholemeal toast and topping with a liberal sprinkle of nutritional yeast – a teaspoon contains over one gram.

With jacket potatoes, the skin is the important bit as it provides a good source of fibre. Eat it with hummus, baked beans or a bean salad to add extra. Evening meals might include vegetable curry with brown rice or lentil bolognaise with wholewheat spaghetti. If you’re a pudding person, go for something with fruit, such as apple crumble made with raisins and an oaty topping; chop fruit into a vegan yoghurt or try a fresh fruit salad with dates and pistachios!

Variety is the key! If you eat a varied vegan diet with plenty of fruit, vegetables, wholegrain foods, pulses, nuts and seeds, you will get all the fibre you need!

Good sources of fibre:

Food Dietary fibre (grams) 
Mixed bean salad (large portion 135g)8.9
Spaghetti, wholemeal (large cooked portion 220g)9.2
Muesli (45g)3.4
Baked beans (half a can 207g)8.4
Potato (baked, medium with skin 180g) 4.7
Wholemeal bread, toasted (2 slices 72g)5.9
Chickpeas, tinned (2-3 tbsp 90g)6.0
Peas, frozen (medium portion 70g) 3.9
Brown rice (medium portion, 180g)2.7
Jumbo rolled oats (small portion, 40g)3.6
Broccoli, steamed (medium portion 80g)3.0

For more information about carbohydrates see here.

About the author
Dr. Justine Butler
Justine joined Viva! in 2005 after graduating from Bristol University with a PhD in molecular biology. After working as a campaigner, then researcher and writer, she is now Viva!’s head of research and her work focuses on animals, the environment and health. Justine’s scientific training helps her research and write both in-depth scientific reports, such as White Lies and the Meat Report, as well as easy-to-read factsheets and myth-busting articles for consumer magazines and updates on the latest research. Justine also recently wrote the Vegan for the Planet guide for Viva!’s Vegan Now campaign.

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