Fibre isn’t something you add. It’s how wheat is built.

January is when fibre suddenly becomes very loud.

We hear a lot about eating more of it, cutting things out, fixing ourselves, starting again. Fibre gets lumped into the same conversation as resolutions and resets, as if it were something we’ve all been forgetting to do properly. Instead, this month we’re slowing the conversation down. Over a short series of articles, we’re unpacking what fibre actually is in wheat, how it behaves in pasta, and why wholegrain doesn’t have to feel heavy or difficult when it’s made with care. No rules. No diets. Just a closer look at how grain works when you give it time.

What fibre actually is in wheat

So let’s start with the basics, because fibre is one of those words that’s everywhere and yet somehow still misunderstood.

Most of us have grown up thinking about fibre as something you’re meant to get more of. As if it were a vitamin you might be deficient in. Something you add on top of food that’s already there. A cereal promise. A supplement. A box to tick. But that’s not how fibre works in wheat. Not even close. In wheat, fibre isn’t an extra. It isn’t something you sprinkle in later. It’s the structure of the grain itself.

The structure of a wheat grain: bran, germ and endosperm

If you could slice a wheat grain in half and really look at it, you’d see that it isn’t one uniform thing. At the centre there’s the endosperm, a soft, pale core rich in starch and protein. This is the part white flour comes from, and it’s excellent at what it does. Surrounding it are several protective layers known as the bran, and tucked into one side is the germ, small but powerful, containing oils, vitamins and flavour that support the life of the seed.

Those outer bran layers are where most of the dietary fibre in wheat lives. And they’re not there to “speed things up” or “flush you out”. Quite the opposite. Fibre slows digestion down. It can help hold onto minerals as food moves through the gut. It softens the way sugars are absorbed. It feeds the gut gradually, rather than overwhelming it all at once.

What happens when wheat is refined into white flour

When wheat is turned into white flour, the bran and the germ are removed deliberately. The bran is taken away because its fibre and coarse particles interfere with the predictable behaviour bakers need at scale. The germ is removed because it contains oils that shorten shelf life and make flour more prone to oxidation. This isn’t done because these parts are bad, but because refining creates consistency, speed and reliability.

What’s left is useful fuel: starch and protein from the endosperm. It cooks quickly, behaves predictably, and does exactly what it’s designed to do.

But it’s no longer the whole story.

Why wholegrain fibre behaves differently

Wholegrain flour keeps the grain together as a system. The bran, germ and endosperm remain in relationship with one another, much as they were grown. Fibre stays connected to minerals. Oils stay close to flavour. Digestion unfolds more slowly and more evenly.

That’s why fibre in wholegrain foods behaves so differently from fibre that’s added back into refined products. One is part of the grain’s original structure. The other is an isolated component, doing its best to imitate it.

Real fibre doesn’t need to make noise. Its job is quiet but essential: to support gut health, moderate digestion and contribute to steadier energy over time. It does that best when it stays where it naturally belongs. And when that fibre is built into something like pasta, where it’s locked into a dense structure and released gradually during cooking and digestion, it stops being something the body has to wrestle with. Instead, it becomes something the body recognises and handles calmly, step by step.

That’s how we think about grain when we choose whole flours and decide how much of the wheat grain to keep together.

That’s the difference between fibre as an idea, and fibre as food.

If this has changed how you think about fibre, the next piece looks at why wholegrain pasta often feels very different to wholegrain bread, even when it’s made from the same wheat.

Sources

• Pomeranz, Y. (1988) Wheat: Chemistry and Technology
• Delcour & Hoseney (2010) Principles of Cereal Science and Technology
• Kent & Evers (1994) Technology of Cereals
• Posner & Hibbs (2005) Wheat Flour Milling
• Slavin, J. (2013) Fiber and Prebiotics: Mechanisms and Health Benefits
• Stephen et al. (2017) Dietary Fibre in Europe (Nutrition Bulletin)
• EFSA (2010) Dietary Reference Values for Fibre
• Fardet, A. (2010) Whole-grain mechanisms
• Jacobs & Tapsell (2007) Food, not nutrients
• Seal et al. (2006) Whole-grain foods and chronic disease
• Petitot et al. (2009) Pasta structure and starch digestion
• Fardet et al. (2014) Structure–digestibility relationships
• Monro & Mishra (2010) Structure-dependent glycaemic impact
• Guzzo et al. (2022) Stone vs roller milling
• Albergamo et al. (2018) Milling and phenolic compounds

Notes

The information shared here is for general educational purposes and is not medical or nutritional advice.

Individual responses to foods vary. If you have specific dietary or medical concerns, seek advice from a qualified professional.

Further reading

• Delcour, J.A. & Hoseney, R.C. Principles of Cereal Science and Technology
• Pomeranz, Y. Wheat: Chemistry and Technology
• Fardet, A. (2010) Whole-grain mechanisms
• Slavin, J. (2013) Fibre and prebiotics
• EFSA (2010) DRVs for fibre