What is dietary fibre?

Dietary fibre is plant material that is resistant to digestion by the enzymes in the small intestine, but may be partially or completely broken down by bacteria in the large intestine.

It is an essential nutrient required for normal functioning of the gut.

We tend to distinguish between two types of dietary fibre; soluble and insoluble.

Soluble fibre dissolves in water to form a gel in the gut.  It makes stools softer, and easier to pass.  Dietary sources include oats, barley, rye, beans, pulses, some fruit (bananas and apples) and root vegetables.

Insoluble fibre is the fibre the body is unable to digest.  Its function is to pass through the gut undigested, carrying with it waste products that can then be excreted by the body.  It adds bulk to stools, increases the speed of transit time and promotes satiety.  Dietary sources include wheat bran, wholemeal bread and pasta, brown rice, nuts, seeds, lentils, seeds of fruit, potato skins and vegetables.

However, the terms soluble and insoluble fibre are being phased out as often both types of fibre co-exist in foods.  Also, whether the fibre is soluble or insoluble does not always predict how it will impact on your body.  Instead, we think more about the amount of fibre present in food.

Food is classed as high fibre if they contain 6g or more fibre per 100g or are classed as a source of fibre if they contain 3g or more fibre per 100g.

It is worth noting that not all wholegrain foods are high in fibre.

 

Can dietary fibre benefit me?

Dietary fibre plays a key role across a number of health issues.  Diets high in dietary fibre are associated with a lower incidence of cardiovascular diseases, coronary events, stroke, type 2 diabetes, colorectal cancers and constipation.

Eating a higher fibre diet helps to make you feel fuller for longer.  This then helps you to manage your appetite and control your weight.

Studies have shown a link between higher fibre intakes and lower BMI, lower fat mass, smaller waist circumference and reduced weight gains over time in both adults and young people.

 

How much fibre do I need?

The table below shows how much fibre a person needs to meet their daily needs.

Small children should have 15g of fibre daily, this amount rises incrementaly into adolscence and adulthood when we should be consuming 30g daily.

 

In the UK, the average fibre intake for adults is 60% (18g) of what is recommended (30g).

There is no upper limit on how much fibre you can eat.

 

How can I increase dietary fibre?

Practical tips to increase your fibre intake include:

1. Increase your fruit and vegetable intake (take a look at the Increasing Fruit and Vegetables information sheet for simple ways to achieve this).

2. Make toast or sandwiches with wholegrain bread, rolls, pitta or bagels.

3. Choose a high-fibre cereal for breakfast.

4. Add bran, flax seeds or linseeds to your cereal.

5. Add linseeds to yoghurt.

6. Try wholegrain pasta or brown rice.

7. Add beans and pulses, such as barley, beans, peas and lentils to dishes, such as soups, casseroles and stews.

8. Add nuts or seeds to salads, pasta dishes or stir fries.

9. Leave the skin on fruit and vegetables.

10. Choose higher fibre snacks, such as oat cakes, oat based cereal bars, trail mix, popcorn, nuts or edemame beans.

11. Use legume-based dips for veggies e.g. hummus or bean dips.

12. Replace half of the white flour with wholemeal flour in recipes.

13. Make changes to your dietary fibre intake gradually to give your gut time to adjust.

14. Drink plenty of fluid to enable the fibre to work efficiently (at least 8-10 glasses throughout the day).

 

 

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