Glycaemic Index (GI) – line-up of food products based on their influence on blood glucose levels after 2 hours from consumption (postprandial glycaemia).
Product’s glycaemic index and sugar levels.
Glycaemic index only refers to carbohydrates, as fats and sugars do not cause the glucose levels to rise as much. Higher the GI of consumed products means higher glucose levels and insulin production in the body. With products that have high GI, the sugar levels increase rapidly and then drop drastically – below the usual level, which may result in feeling hunger. The most beneficial to consume are products that GI doesn’t exceed 60.
Different sources may give different GI values, depending on the environment of the testing area. Thanks to the knowledge of product’s GI, we can limit the body’s glucose levels by choosing the ones with lower glycaemic index. This makes it easier to go back to appropriate body weight and maintaining it.
To set the glycaemic index of a food product, a testing person is given a specific product containing 50g of digestible carbohydrates. Then, every 15 minutes, for 2 hours, there are tests done to determine the blood sugar levels.
GI = Concentration of glucose in blood after consuming a product containing 50g of carbohydrates : Concentration of glucose in blood after consuming 50g of glucose
Calculating the glycaemic index for a whole meal
You can calculate the glycaemic index of a whole meal that contains different products. In order to do that, we summarise the carbohydrates contained in specific products. Then, count the percentage of carbohydrates from individual products in carbohydrates in the whole meal. Divide those results accordingly by glycaemic index of individual products. The last step is summarising the received results, which will allow us to find the glycaemic index of the whole meal.