Why do we need dietary fibre?

My mum used to call it roughage and it is almost impossible to have missed the various health claims for what happens when you eat it.  Nowadays, we are even being told that certain bits of fibre are better than others and knowing what to incorporate into a monthly diet plan is more confusing than ever.

In this article, we will explain what exactly good fibre is along with the difference between insoluble and soluble fibre. We’ll recommend fibre rich foods and talk you through the benefits of consuming them.

What is fibre?

Fibre can be roughly defined as the indigestible part of plant-based food. Measuring the amount of fibre in food has proved problematic so, as a result of these technical difficulties, you will find reference to non-starch polysaccharides (NSP) as well as dietary fibre in the literature on the subject. The differences are that dietary fibre includes NSP but that NSP as a defining category does not include all that is dietary fibre. 

Instead, NSP is a method of measuring what in food constitutes the indigestible portion. The reason for referring to NSP is that NSP is the main component in plant cell walls and therefore is the largest single contributor to the ‘fibre’ content of a food. It can be relatively easily measured to give food scientists a reasonably accurate and reliable measurement tool.

Types of fibre

When you look closely at fibre, it is best thought of as a family as its members are complex carbohydrates and not all of them are fibrous in structure. There are two main classes of fibre: soluble and insoluble.

Soluble fibre

Soluble fibre dissolves in water forming a gel.  In the body, this gel binds with other contents of the stomach. This means that digestion is slowed for whatever is bound in the gel.

Soluble fibre does not pass through the intestines and out, instead, once it reaches the colon it ferments.  This produces gas, but much more importantly fermentation results in additional nutrient absorption.  The fermentation action of healthy colon bacteria also releases short-chain fatty acids.

We are still discovering the health benefits of colonic bacterial fermentation from soluble fibre, including the suppression of cholesterol production, stabilisation of blood glucose levels, and promotion of a healthy immune system.

A number of soluble fibre products have recently been developed. They are coming to the market and being tested right now.

Insoluble Fibre

This type of fibre does not dissolve in water, and cannot be digested. Instead, insoluble fibre passes through the body attracting water to it.

Indigestibility and the fact that it draws water into the gastrointestinal tract make insoluble fibre a great way to prevent constipation. With a healthy insoluble fibre intake, stools are soft and easy to pass.

This is a great way to prevent diverticular disease – a condition that affects up to one in two people over the age of 50. Of those, a further one in 20 develop additional complications.

Why is fibre important?

Fibre is essential to maintain a healthy gastrointestinal tract. To maintain a healthy gut, we need to eat a recommended 25-30g of fibre a day. In surveys of the UK, the average intake is between 12g and 15g, with similar results for the US.

The health benefits of fibre are still being investigated but, so far, having a good fibrous diet has been linked to a lower incidence of colon cancer and diverticular disease. It is also linked to lowering cholesterol levels as well as the risk of heart disease, strokes, and cardiovascular diseases.

For an athlete, the health benefits long term are great, however, fibre has a more immediate benefit. As mentioned before, fibre is essential for a healthy gastrointestinal tract.  If the gut does not work right then all the healthy eating in the world amounts to very little.  A healthy gut maximises the absorption not only of proteins, fats, and carbohydrates but also the micronutrients (i.e. vitamins and minerals) that are essential to health.

By eating a variety of fibre rich foods you will also be getting a wide spectrum of vitamins, minerals, as well as phytonutrients that each have their own unique health benefits. For example, the pigment lycopene found in tomatoes is known to have preventative effects for cancer or there are anti-inflammatory properties in spinach due to the lutein it contains.

Fibre also promotes the action of healthy bacteria as well as proper function.  The benefit of this is that the body has a more active and effective immune system.  With the prevalence of upper respiratory tract infections in many a hard training athlete, this is a welcome boost.

How to get more fibre in your diet?

Eating a healthy amount of fibre is not difficult, even if the average UK resident only eats half the recommended amount. Eating five portions of fruit and vegetables a day should be enough to ensure a healthy fibre intake. Interestingly, however, the average UK resident only averages around half of the recommended five a day.

Moving from an average intake to the recommended intake needs to be done carefully taking a week or more to build up.  If you don’t then you risk a dramatic decrease in transit time – otherwise known as diarrhoea.

High fibre foods

In the UK, a food can be labelled ‘high fibre’ if it contains more than 6g of fibre per 100g of the product.

Broccoli is a powerhouse food packing a heavyweight nutrient punch in terms of vitamins and minerals with a healthy jab of fibre. Peas and beans also have a healthy dose of fibre as do sweetcorn, spinach, Brussels sprouts, kale, turnip, and other greens.  

Potato skins are rich in fibre and you don’t have to stick to just baked potatoes to eat the skin. Instead of peeling, scrub with a vegetable knife and use as normal for extra fibre, vitamins, and minerals. Wholegrain and wholewheat food varieties are also high in fibre and make a good contribution to a healthy daily intake.

If it’s a fruit or vegetable and it is whole, it is going to have fibre. Even dried fruits, coconut and bananas make a healthy contribution.

Sources of insoluble fibre

A wide variety of whole grains and pulses are a source of insoluble fibre. These fibre rich foods include:

  •   Beans
  •   Brown rice
  •   Edible seeds
  •   Lentils
  •   Maize
  •   Oats
  •   Pulses
  •   Wheat bran
  •   Wholegrain and wholemeal breads
  •   Wholegrain and wholemeal cereals
  •   Wholemeal pasta
  •   Whole wheat flour

Sources of soluble fibre

Fibre foods such as fruits and vegetables are a fantastic source of soluble fibre. Examples of soluble dietary fibre include:

  •   Apples
  •   Barley
  •   Citrus
  •   Guar gum
  •   Legumes
  •   Oats
  •   Pears
  •   Strawberry
  •   Barley
  •   Broccoli
  •   Carrots
  •   Beans
  •   Psyllium

Fibre and fluid

A healthy fluid intake of at least 1.5 litres a day is always a good idea but it is especially important when you eat a good fibre-full diet.

Dietary fibre acts much like a sponge. When you eat it the fibre tends to be dry and, without fluid to lubricate it, it becomes a tough job to get it through to the other end. To illustrate this, get a sponge and try to push it through the cardboard tube in the middle of a toilet roll. When dry, this is not easy but when the sponge is wet it slides through easily.

The same is true for your body. If you do not supply the fluid you need to help the passage, then some will be pulled from other parts of your body but essentially the fibre is going through dry. Dry fibre passing through you is not healthy as it cannot perform its proper function without adequate hydration. Like your brain, your gut performs best when well hydrated

Final thoughts

Fibre is an important inclusion in a balanced diet, promoting gut health and proper body function for a variety of organs. It is essential to incorporate fibre rich foods such as fruits, vegetables, and grains to truly feel the effects of this crucial nutrient.

Our high protein ready meals provide a good source of fibre by incorporating fibre foods such as brown rice, carrots, and beans. Browse our extensive selection, safe in the knowledge that you will consume a healthy, balanced diet.

Complete article provided free with our Diet Packages.

Back to Support Zone