Glycemic index is a rating system which determines how quickly the body processes carbohydrate foods into the bloodstream as glucose. Each carbohydrate food is given a rating from 0-100, with 0-50 being classed as low GI and 50-100 as high GI.
High GI carbohydrates are broken down quickly by the body and rapidly increase blood glucose levels.
Low or even medium GI foods are broken down slowly and cause a steady rise in blood glucose levels.
Choosing more low GI foods than high GI foods can help to minimise a rapid rise in blood glucose levels and benefit health in the long term by reducing the risk of diabetes complications.
High GI foods are not necessarily unhealthier than low GI foods. For example, a watermelon is classified as a high GI food, whereas chocolate can be a low GI food. This is due to the fats added which slow down the absorption of carbohydrates in the chocolate. Therefore, eating a diet with solely low GI foods could become unbalanced. A glycemic index can be helpful in discovering which foods may cause a blood glucose spike, but a balanced and healthy diet with a variety of different food groups is key.
BDA (2020) Glycaemic Index (GI): Food Fact Sheet. Available at: https://www.bda.uk.com/resource/glycaemic-index.html (Accessed on 24 November 2022).
NHS (2022) What is the glycaemic index (GI)? Available at: https://www.nhs.uk/common-healthquestions/food-and-diet/what-is-the-glycaemic-index-gi/ (Accessed on 23 November 2022).