Why more fibre isn’t always better.

At some point, most conversations about fibre drift towards numbers.

More fibre is better. Higher percentages are better. If wholegrain is good, then surely more wholegrain must be better still. It’s an easy conclusion to reach, especially in a world where food is often reduced to targets and totals. But wheat doesn’t really work like that.

A wheat grain isn’t a simple shell wrapped around starch. It’s layered, deliberately and precisely. Each layer has a job to do, and once the grain is milled, cooked and eaten, those layers don’t all behave in the same way.

The outer bran layers and digestion

The very outer layers of the grain exist first and foremost to protect the seed. They’re tough, fibrous and resistant by nature. In the field, that toughness is essential. It helps the grain survive weather, pests and time. But once those layers are ground into flour, their job changes. They’re slow to soften, slow to hydrate, and not especially generous when it comes to digestion.

The inner bran layer and extraction balance

Just beneath them sits a different layer altogether. Finer, more delicate, and often overlooked. This inner layer of the bran is rich in fibre too, but it’s a different kind of fibre. It carries minerals. It contains enzymes. It hydrates more gently and ferments more steadily. This is where much of the grain’s flavour and functionality live.

When flour keeps everything indiscriminately, including the harshest outer layers, fibre can feel heavy and abrasive. It can dominate the eating experience rather than support it. When flour removes too much, fibre disappears altogether, along with much of the grain’s depth, balance and character.

The sweet spot sits somewhere in between, and finding that balance is a big part of how we think about milling choices and extraction rates.

Flours that are nearly whole, but not aggressively so, tend to behave best. They retain the most useful layers of fibre, the ones that nourish, buffer and slow things down, while leaving behind the parts that mostly add resistance. Digestion unfolds more calmly. Energy is steadier. The grain feels complete rather than demanding.

This is why wholegrain doesn’t have to mean “hard work”. And why chasing fibre as a number can miss the point entirely.

Milling judgement and extraction rates

Good milling isn’t about stripping the grain back to nothing, nor is it about keeping everything out of principle. It’s about judgement. Understanding which parts of the grain to respect, and which parts to let go, so that what remains can actually do what it’s meant to do.

When fibre is kept in the right proportion, and in the right place, it stops feeling like something you have to manage. It becomes part of a food that simply makes sense to eat.

In the final article of this series, we look at how slow drying changes the way wholegrain pasta delivers energy, and why time and temperature matter just as much as the grain itself.

Sources

• Delcour, J.A. & Hoseney, R.C. (2010) Principles of Cereal Science and Technology
• Pomeranz, Y. (1988) Wheat: Chemistry and Technology
• Van der Kamp, J.W. et al. (2014) Dietary fibre and whole grains in wheat
• Hemery, Y. et al. (2007) Biochemical markers of wheat aleurone layer
• Brouns, F. et al. (2012) Wheat aleurone: separation, composition and health aspects
• Fardet, A. (2010) New hypotheses for the health-protective mechanisms of whole-grain cereals
• Jacobs, D.R. & Tapsell, L.C. (2007) Food, not nutrients, is the fundamental unit
• Seal, C.J. et al. (2006) Whole-grain foods and chronic disease

Notes

The information shared in this article is intended for general educational purposes and reflects current food science research on grains and pasta making. It 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
• Brouns, F. et al. (2012) Wheat aleurone: separation, composition and health aspects
• Hemery, Y. et al. (2007) Biochemical markers of wheat aleurone layer
• Fardet, A. (2010) New hypotheses for the health-protective mechanisms of whole-grain cereals

These references focus on grain structure, fibre fractions and processing choices, rather than simple fibre targets or dietary rules.