What is the Glycaemic Index?
The Glycaemic Index (GI) of food reflects how quickly the carbohydrate component of that item is digested and absorbed by the body and into the blood stream. This will therefore determine the impact that food will have on your blood glucose levels.
Glycaemic Index is represented by a numbering system where each food or product is allocated a figure based on its absorption, placing it in the category of ‘low GI’, ‘moderate GI’ or ‘high GI’. These categories are illustrated below.
What do the GI numbers mean for me?
Simply put – the lower the GI, the more gradual and sustained the energy.
So if you eat a food that is high GI, your body will receive energy very quickly and will also use it very quickly. If you eat a food lower in GI, your body will receive and use the energy at a more gradual rate – this is optimal to keep you going!
This concept is reflected by your blood glucose levels (glucose being the energy we discussed). The diagram below demonstrates this idea.
As you can see, the degree to which your blood glucose levels (BGLs) peak and for how long is directly related to the GI of the food you are eating. A more moderate peak and release is desirable as it provides you with energy for a longer period of time and prevents you from having a sudden burst of energy and then ‘crashing’.
What are the benefits of lower GI foods?
- They provide you with a better quality of energy that will help you to get through the day without becoming prematurely fatigued.
- They help with mental function and concentration – an important one for children in the classroom!
- They keep you fuller for longer so can be useful for weight management.
- It is better for your health in the long term if your blood glucose levels are more consistent over the day. This applies to everyone, not only individuals with diabetes.
- They are fantastic for individuals with diabetes. Low GI products help to control your blood glucose levels by releasing glucose more gradually into the blood stream and over a longer period of time. This helps to sustain energy and BGLs from one meal to the next. In the long term, it decreases the risk of diabetes related complications occurring.
- Eating low GI foods in the same meal as higher GI foods will lower the glycaemic load of a meal. Meaning the overall GI of that meal is lowered.
Glycaemic index – low GI and high GI foods
Here are some examples of foods that are likely to be high GI and those likely to be low GI (these may vary between brands):
The symbol below is found on products that have had their GI reliably tested. To qualify for the symbol, a food product must be a good source of carbohydrate and must meet criteria concerning energy, fat, sodium and fibre content. These are healthy, low GI options.
You can search for the glycaemic index of individual food items on the University of Sydney’s website
Be aware of the glycaemic index. Both high GI and low GI foods can be incorporated into a healthy diet. It is a matter of eating more low and moderate GI foods, not excluding high GI foods all together. A low GI food does not always mean that the food should be consumed regularly. You should also consider how healthy the food is overall by considering the fat, sodium and fibre content. The key is to be aware of the glycaemic index and make suitable choices that are well balanced.
For more information about glycaemic index, the GI of certain foods or any other GI related questions, make an appointment with our dietitian Belinda Elwin. ENT Wellbeing can be reached on 1300 123 368 and are happy to help with any diet related issues or questions. Contact us today.