A loaf of soda bread cut into slices

Spotlight on… high-fibre diets

Why is fibre important? Nutritionist Jo Lewin explains how upping your intake can have a positive impact on health and offers invaluable tips and the best high-fibre recipes to ensure you're getting your daily dose.

Including enough fibre in our diets is essential for a number of reasons, including healthy bowel function. Studies have also found that getting the recommended amount can reduce your risk of certain health issues, such as cancers, coronary heart disease and obesity.

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There is no Reference Intake for fibre, but health experts recommend we have at least 30g a day, depending on age and gender. Sadly, few of us achieve these levels. To increase your intake, choose foods with a higher fibre contribution. Get used to reading labels and look for foods that contain 6g fibre or more per 100g (or at least 3g per 100kcal) – these are considered to be high-fibre foods, while those containing at least 3g of fibre or more per 100g (or at least 1.5g per 100kcal) are considered to be a source of fibre.

The father of the fibre hypothesis: Dr Denis Burkitt

Dr Denis Burkitt was the first researcher to connect a high-fibre diet with better health. Studying rural communities in Africa, he noticed that eating a traditional diet resulted in healthier stools and bowel movements compared to the Western diets of those living in cities. Those eating local produce had extremely low incidences of diabetes, irritable bowel syndrome, constipation, diverticular disease, colon cancer or heart disease compared to those consuming a Western diet. After looking at many factors, Dr Burkitt concluded the high amount of fibre in traditional diets was necessary for maintaining good health.

Health implications

A fibre rich diet can help to prevent constipation (see below), diverticulosis, bowel cancer and haemorrhoids. In conjunction with increasing your fibre intake, be sure to keep fluid levels up to help make stools are easier to pass. Dietary fibre can also help obesity by slowing down digestion (keeping us fuller for longer) and helping the release of glucose and insulin. Soluble fibres have been shown to help normalise serum cholesterol levels by binding directly to cholesterol, decreasing the chance of reabsorption and promoting excretion. Fibre also feeds our gut microbes, the beneficial community of microorganisms that reside in our intestines, this helps support our health and maintains our bowel regularity.

A note on constipation

People are constipated when they strain to have a bowel movement, have hard stools, infrequent or incomplete bowel movements or discomfort. Some people feel fatigue, aches and mental sluggishness from constipation. Constipation affects women twice as often as men and is more common in people over 65. Although age is commonly listed as a cause of constipation, it is attributed more to the result of lifestyle. Eating low fibre, packaged or prepared foods, certain medications and a lack of mobility can all contribute to constipation.

Women often notice that their bowel habits change at various times in their menstrual cycle. Pregnancy is a common but temporary cause and it may also be caused by an underactive thyroid. Bowel movements should be painless. If you experience pain or blood during a bowel movement, see your GP.

It is normal to have one to three soft bowel movements each day. Optimal bowel transit time is 12 to 24 hours. Slow bowel transit time raises the risk of colon disease and contributes to other health problems.

Types of fibre

There are a number of different types of fibres, typically classified as either soluble or insoluble.

Soluble fibre

Soluble fibre can be digested by the body and increases water content in the intestine to make stools softer. It’s made up of gums and other constituents of plant cells, and plant cell walls that swell in water. Soluble fibre promotes the excretion of cholesterol and can be helpful for those suffering from haemorrhoids.

Insoluble fibre

Insoluble fibre is traditionally known as roughage. It consists mainly of cellulose, which absorbs water but passes through the bowel almost undigested. Foods rich in insoluble fibre fill you up and are effective at increasing stool size and bulk, thus promoting regular bowel movements.

Foods containing Soluble Fibre

  • Oats
  • Lentils
  • Beans
  • Fruit, including pears and apples

Foods containing Insoluble fibre

  • Wheat bran
  • Wholegrain cereals
  • Dried fruits
  • Corn, including popcorn

Recommendations

Get more fibre in your daily diet by…

  • Eating at least five portions of fruit and vegetables each day
  • Making wholegrains the rule and processed grains the exception
  • Starting the day with a high-fibre breakfast cereal (bran, oats or wholegrain) topped with dried or fresh fruit. Most cereals give an average of 3g fibre per serving
  • Choosing wholemeal, wholegrain, granary or multiseed bread
  • Adding legumes such as kidney beans, lentils and chickpeas, which have a large amount of dietary fibre, to stews and casseroles

Things to watch

Increase the amount of fibre in your diet slowly. A quick change from a low-fibre to high-fibre diet can cause gas, cramps and bloating. If you have been diagnosed with a condition such as diverticulitis or colitis, refer to your GP or healthcare professional for the correct dietary advice for your condition.

High-fibre recipe suggestions

Browse our high-fibre recipe collection or try our recipes below.

Add extra vegetables to lasagne or chilli:
Five-veg lasagne
Vegetable & bean chilli

Add peas, beans and lentils to stews and casseroles:
Spicy chicken & bean stew
Herby bean sausage stew

Smart high-fibre snack ideas:
Edamame & chilli dip with crudités
Warm Mexican bean dip with tortilla chips

Choose wholegrain or brown toast topped with:
Gigantes plaki

Soups and salads packed with fibre:
Indian winter soup
Courgette pea & pesto soup
Warm roasted squash & puy lentil salad
Warm chickpea chilli & feta salad

Soaking or stewing dried fruit will provide a great source of soluble fibre and a yummy pudding option:
10-minute winter fruit compote

More in health and nutrition:

Women’s health
Men’s health
Fitness & nutrition
Special diets
Eating for ill health
Healthy eating
Healthy cooking
Ingredient focus


This article was updated on 11 December 2019 by Kerry Torrens.

Kerry Torrens BSc. (Hons) PgCert MBANT is a Registered Nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.

Jo Lewin is a registered nutritionist (RNutr) with the Association for Nutrition with a specialism in public health. Follow her on Twitter @nutri_jo.

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