Fibre and GI play an important role in managing diabetes, supporting overall good health, digestive system and gut health, appetite regulation and reducing cholesterol.


What is glycemic index (GI)?

The glycemic index (GI) is a measure of how quickly carbohydrates are broken down and absorbed into the bloodstream. The higher the GI, the faster the food will be digested and absorbed, which will lead to a rapid increase in blood sugar levels. Alternatively, the lower the GI, the slower the food will be digested and absorbed, meaning a more gradual increase in blood sugar levels will occur. You can think of GI like lighting a sheet of paper (high GI foods) vs a sheet of bark (low GI foods) on fire. The paper will burn very fast, whereas the sheet of bark will burn slowly over time.


What is fibre?
Fibre is a type of carbohydrate that is more complex for the body to digest, therefore it takes longer to digest and absorb. This means foods that are higher in fibre tend to have a lower GI than foods with low amounts of fibre. Fibre also has many other benefits such as promoting regular bowel movements, reducing cholesterol, improving gut health and assisting in appetite regulation.


Which foods are high in fibre?
Foods that are high in fibre include fruits, vegetables, legumes, nuts, seeds and wholegrains. Legumes are foods such as lentils, chickpeas and beans. Examples of wholegrain foods include brown rice, quinoa and wholemeal breads and pastas. It’s important to note that the skin of fruits and vegetables contain a lot of the fibre (and many other nutrients). This is why it’s important to use the whole of the fruit or veg as a part of meals or snacks. This also means that majority of fruit are actually classified as low GI, despite the moderate amounts of carbohydrates and
sugar. On the other hand, fruit juices are higher in GI as the fibre is removed from the fruit.


How much fibre should I be having per day?
The recommended daily intake of fibre per day is:

  • Men: 30g/day
  • Women: 25g/day

Reading nutrition labels
Aim for 6g of fibre per 100g or more.

What does 30g of fibre per day look like?


Meal Food items Fibre  Total fibre
Breakfast (e.g. cereal)
  • 2 weetbix
  • 100g mixed berries
  • 250ml milk
  • 3g
  • 5g
  • 0g


Morning tea
  • Medium apple
  • Handful almonds
  • 4g
  • 3g


Lunch (e.g. sandwich)
  • 2 slices of wholemeal bread
  • 1 whole tomato sliced
  • 50g spinach
  • Protein of your choice (e.g. chicken, tofu)
  • Sauce
  • 5g
  • 1g
  • 1g
  • 0g
  • 0g
Afternoon tea
  • 40g low salt popcorn
  • 5g
Dinner (e.g. rice bowl)
  • 1/2 cup cooked mixed vegetables
  • 1/3 cup cooked brown rice
  • Protein of your choice
  • Sauce
  • 4g
  • 1.5g
  • 0g
  • 0g
Supper Of your choice
Total 32.5g


In summary 

The GI of a food will impact how fast it is digested and ultimately the rate at which your blood sugar levels rise. Foods with high fibre tend to have a lower GI than foods with low fibre. By including more high fibre foods in your diet, this will help manage your diabetes and support overall good health. This can be done by adding more fruits, vegetables, wholegrains, nuts, seeds and legumes to your meals or snacks.




Josh Wernham
Student Dietitian 

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