How does fibre affect glucose responses?

How does fibre affect glucose responses?

Do you experience those mid-afternoon energy slumps? It might be related to your blood glucose levels. Keep reading to find out how dietary fibre can support healthy glucose levels.
Thalia Ignatoff
by Dr Caitlin Hall (APD, PhD)
Chief Dietitian and Head of Clinical Research

Fibre is best known for its role in keeping us regular. But what most people don’t know is that consuming a high fibre diet is a powerful way to support healthy blood glucose responses.


  • Our bodies need simple sugars (glucose) for energy. It’s the fuel that powers our brain. That doesn’t necessarily mean we should eat a lot of it.
  • Having consistently elevated levels of blood glucose – called hyperglycaemia – is linked to a range of health conditions like diabetes, heart disease, obesity, and dementia.
  • Dietary fibre is a simple yet powerful way to maintain good glucose control and reduce the risk of chronic disease.
  • Fibre works in two distinct ways to stabilise blood sugar levels, which can be described as “fast” and “slow” processes.
  • Fast-acting effects work immediately after a meal. Fibre slows the digestion of food and the absorption of glucose into the bloodstream, resulting in a lower and slower glucose (and insulin) response.
  • Slow-acting effects are associated with changes to the gut microbiome. Our gut microbes ferment fibre to produce important substances called Short-Chain Fatty Acids (SCFAs). SCFAs act via a number of pathways to promote good glucose balance and insulin sensitivity.


What does glucose do in the body?

When we eat a high sugar or carbohydrate-containing meal, it’s broken down into its simplest form: glucose. The rate at which glucose is released into the bloodstream is called its glycaemic index. Foods that cause a rapid spike in blood glucose levels are said to have a high glycaemic index. One example is refined carbohydrates found in white bread, cakes, cookies, pastries, and white sugar. As these foods are stripped of fibre, vitamins, and minerals, they’re quickly broken down and absorbed into the bloodstream. We’ll come back to this later.

In response to elevated glucose levels, our pancreas releases a hormone called insulin. Insulin’s main job is to direct glucose from the blood into liver, fat, and muscle cells. Our blood glucose levels then start to decrease back towards a normal range. In response to this drop, the pancreas stops releasing insulin. The release of insulin is proportional to glucose levels in the blood. So a sugar-coated donut will require more insulin than say, a sirloin steak.

If you tend to eat a lot of sugary foods and refined carbohydrates across the day, it’s likely that you experience the extremes of both high and low blood glucose (you might have heard of blood sugar spikes and crashes). This can affect things like energy, sleep quality, hunger, appetite, and exercise. 

Repeatedly having high blood glucose levels – called hyperglycaemia – is linked to a range of health conditions like diabetes, heart disease, and obesity.


What happens in diabetes?

There are two main forms of diabetes:

1️⃣  Type I diabetes is an auto-immune condition where little to no insulin is produced in the pancreas. This means that glucose is not taken up by cells, and remains dangerously high in the blood. Life-long use of insulin medication is needed to maintain glucose control.

2️⃣  In Type II diabetes, there are two interrelated problems:

  • Muscle, liver, and fat cells become resistant to insulin, causing blood glucose levels to rise.
  • The pancreas is unable to produce enough insulin to keep up with increasing blood glucose levels.
  • Insulin resistance is linked to a proinflammatory state, which can potentially cause damage throughout your body, including the blood vessels, heart, brain, and liver.

Insulin medication may also be required for some people. Unlike Type I, diet and lifestyle changes are highly effective at improving insulin sensitivity and even reversing Type II diabetes.


Fast-acting effect of fibre

The fast effects of fibre work by reducing the post-prandial glycaemic response. It’s a mouthful, so let’s break it down.

🥗  Post-prandial means “after a meal”.

📈  Glycaemic response refers to the rise of blood glucose levels in response to an input (usually food).

When we put it together, adding fibre to a meal reduces the rise of blood glucose in response to that meal. It does this by slowing down the digestion and absorption process, leading to a more gradual release of glucose into the bloodstream. This slow rise in blood glucose allows insulin to more efficiently do its job.

For example, consuming a chocolate croissant (refined carbohydrates) will produce a faster and more rapid rise in blood glucose, followed by a sharper descent. The wholegrain wrap (high-fibre complex carbohydrate) will produce a slower and more gradual blood glucose response. It flattens the curve.

Unlike refined carbohydrates that produce rapid spikes and crashes in blood glucose, high-fibre meals will leave us feeling more energised and feeling full for longer.  


Slow-acting effects of fibre

“Slow-acting” effects comes from research that looks at the ability of the gut microbiota to ferment fibres and produce potent anti-inflammatory agents called Short-Chain Fatty Acids (SCFAs). SCFAs produced in the gut provide important benefits to glucose and insulin metabolism. SCFAs also promote the release of a hormone (called GLP-1) that alters gut transit time and regulates fat storage (improving insulin sensitivity). 

One of the most effective ways to increase SCFA production in the gut is to consume fermentable fibres, which can be found in foods like chicory root, asparagus, onion, garlic, beans, and artichokes.


myota's Metabolic regulator fibre mix 

Research is an essential part of what we do here at myota. We’ve spent a great deal of time and research to study combinations of fibres that produce the greatest benefits to glucose responses. As a product of this research, we’ve formulated the Metabolic Regulator mix. This mix combines viscous (gel-forming) and fermentable (SCFA-producing) fibres that address both the fast and slow-acting mechanisms.   

Find out more on our product page. and check out our nutritional facts.