Fibre: why do we need it?

August 5, 2019 6:12 am Published by 4 Comments


We need to eat more fibre, the doctors say. We need to choose products high in fibre, the advertisers proclaim. We need this particular ‘fibre-licious!’ new ingredient on our kitchen shelves, the marketers shout. They’re all united in their drive to get more fibre into the nation. But why? What exactly is fibre – and why do we make such a big deal about it?

Bothered about fibre in your diet?

What’s fibre?

Fibre is a specific type of carbohydrate (sometimes called ‘roughage’ or ‘bulk’). It’s often referred to specifically as ‘dietary fibre’. It’s the part of food that our bodies don’t break down during digestion. There are two types of it – soluble and insoluble – but for most of us, it doesn’t much matter which type a food contains. Fibre-rich foods tend to include both soluble and insoluble fibre, and the interaction between the two types is complex. In this blog, we’re using ‘fibre’ as a simple term, covering them both.

That’s got that sorted out. But why do we need so much of it?

Fibre: for tums and bums

Most people think of ‘down below’ when they think of fibre. But to work out how fibre keeps our bowels in order, we need to start by looking a little higher up first. Fibre actually begins its vital work in our digestive tract. Here, the fibre we take in in food remains undigested and passes into our intestines, where it absorbs water. It then creates bulk, prompting our muscles to push it, and other waste, out of the body.

Eating plenty of fibre thus prevents constipation. But it does more than that: the European Prospective Investigation into Cancer and Nutrition has found that a high-fibre diet, particularly one derived from cereals and wholegrains, reduces the risk of developing bowel polyps (the precursor to bowel cancer) and this type of cancer itself.

And fibre is good for tums and bums in another way: it helps to keep us at a healthy weight. The bulk provided by fibre gives us a feeling of fullness, which staves off hunger pangs, helping us to properly regulate our diet. That’s good news all round: a healthy weight lowers our risk factors for diabetes, stroke, cancers and heart disease.

Fibre: for cholesterol

Fibre is also vital for healthy cholesterol levels. In our digestive systems, fibre binds with cholesterol particles and moves them out of our bodies before they’re absorbed. Fibre thus reduces the levels both of ‘bad’ LDL (low-density lipoprotein) cholesterol and of overall cholesterol in our bodies. Again, that’s good news for anyone worried about their risk of strokes.

Fibre: for blood pressure

Fibre also helps keep our blood pressure at a healthy level. Researchers at the Tulane University School of Medicine carried out a comprehensive analysis of data on fibre and health from 25 clinical trials, publishing their data in the Journal of Hypertension. They noted a strong link between increased fibre and healthy blood pressure: people with high blood pressure who ate more fibre saw both their systolic and diastolic blood pressure drop. Those with normal blood pressure saw a small (but healthy) decrease too.

Fibre: for blood sugar

Fibre is a carbohydrate, but it’s not digested as other carbohydrates are. While other, refined carbohydrates cause a spike in blood sugar as they release their energy, fibre simply passes through intact, without producing this reaction. Blood sugar levels therefore remain more stable, protecting against the risk of developing Type 2 diabetes.

What happens if we don’t get enough fibre?

If you’re not eating enough fibre, you’ll probably first notice it when you go to the loo. You’re likely to find it harder to ‘pass a motion’ and may become constipated. You might also notice more swings in blood sugar – you’ve eaten your fill, but the feeling of satisfaction wears off very quickly, leaving you feeling tired and faint and desperate for more food. Over time, the rollercoaster of highs and lows in blood sugar will probably see you put on weight.

With increased weight, and difficulty managing your appetite and energy, you’ll be more at risk of Type 2 diabetes and strokes. You might also find yourself diagnosed with high blood pressure or high cholesterol.

How do I get enough fibre?

There are tablets, liquids and supplements you can take to boost your fibre intake, but as you might expect, at Naturally Good Food we greatly prefer the natural route! If you’re short of fibre, it’s easy to add more to your diet. Simply eat plenty of fresh fruit and vegetables, and a good amount of wholefoods. With wholefoods, you get the ‘whole’ of the food, with the edible fibrous outer husk and bran included.

In the NGF Wholefoods section you’ll find pulsesbeans, peas, lentils and chickpeas, both dried and tinned, in bulk and in small packets. We’ve also got brown rice, wholewheat pasta and noodles, and grains such as quinoa, barley, millet, buckwheat, couscous, rye and spelt. We stock wholemeal flour to make your own bread and a vast range of wholegrain cereals, as well, of course, as many types of oats. There are nuts too: almonds, brazils, cashews, hazelnuts, walnuts, pecans, macadamias, peanuts and pistachios; a fantastic range of fibre-rich seeds; and a wonderful selection of dried fruitdark, juicy organic apricots, raisins, currants and sultanas, figs, dates and prunes.

We’re a little bit obsessed with fibre at Naturally Good Food. Over the next few weeks, we’ll be taking a look at just how much we need in our diets and thinking more carefully about how best to incorporate it. Watch this space!

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This post was written by Yzanne


  • RP says:

    Why do we need it? Technically we don’t. There are studies such as this which cast doubt on the simple model of fibre proffered by doctors:
    I’ve also seen a large meta analysis of studies on fibre that suggests the data doesn’t quite back some of the claims.
    That isn’t to say it doesn’t have benefits for gut biome etc but I suspect anyone reading this on a whole food site need to increase it massively or worry about the(I suspect) plucked from the either RDA- it’s pretty hard to keep fibre at low levels if your plant based; I know because I have IBS and have found lower fibre intake improves symptoms but it is pretty hard to achieve and means although I avoid junk per se I do happily include some white flour, white rice etc despite lower nutritional levels

    • Yzanne says:

      Yes, there is a place for white flour/rice etc. in many people’s perfectly healthy diets. Thanks for sharing those links and articles.

      Best wishes,

      Yzanne Mackay
      Writer and Editor
      Naturally Good Food

  • RP says:

    I suspect anyone reading this on a whole food site WONT need to increase it massively (EDIT)

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