The Usage of Glycemic Load
Introduction
Carbohydrates are one of the primary nutrients we consume on a daily basis. Nowadays, they are one of the main topics people tend to discuss in nutrition. Consequently, an important question comes up - how can we modify or control the glucose level changes in the blood after eating certain foods?
For a while now, the answer to the question was widely accepted to be the glycemic index. However, the application of the glycemic index is not entirely practical to measure changes in glucose levels. The corrected form is the glycemic load which will be discussed in further detail in this article.
When we consume carbohydrates, our digestive system breaks them down into glucose and transports them into the blood, where our blood glucose level increases. Now, the main concern is how much it increases after eating certain foods. The glycemic index is used to conceptualize and visualize this change.
Glycemic Index
The glycemic index is a scale of values from 0 to 100 that informs us how quickly a food raises blood glucose levels. It is standardized using white bread or sugar.
If a food has a glycemic index near the lower value, it digests slower and raises blood glucose levels gradually. Whereas if it is within the high interval, it raises blood glucose levels quickly (1).
In addition, to understand how the glycemic index is affected, you can read our article that discusses what affects the glycemic index.
The glycemic index scale falls into 3 categories:
- Low <55
- Medium 56-69
- High >70
However, the glycemic index doesn't consider all the variables, such as serving size, and because of that, it has lower practicality.
To understand the glycemic index more deeply, you can read the article that explains the glycemic index in detail.
Glycemic Load
The glycemic load is a tool derived from the glycemic index. However, it adds another important layer that the glycemic index doesn't consider: the serving size of the food itself.
To find out the glycemic load of the given food, we can apply this equation:
Glycemic load = glycemic index × amount of carbs in one serving of the food /100
The scale of glycemic load also has 3 categories:
- Low 0-10
- Medium 11-19
- High >20
The glycemic load considers how much one average serving size of food will raise your blood glucose levels (2).
Watermelon is a perfect example to showcase the difference between glycemic index and glycemic load. The glycemic index of watermelon is 76, which is considered very high. However, the amount of carbs in a serving of watermelon is 8g. This means that the glycemic load of watermelon is 6. Watermelon can be eaten without much concern in moderation because the serving size of watermelon has a low glycemic load.
Why Does This Matter?
In diabetes and prediabetes, it is essential to be careful not to spike up blood glucose levels. For this purpose, people with diabetes use the glycemic index and consume low glycemic index foods to prevent blood glucose spikes. Although the glycemic index is a helpful tool, as mentioned above, it doesn't consider the serving size. In turn, the glycemic load is a more practical tool considering the serving size.
As a diabetic or prediabetic person, knowing the serving size of each food you eat and its glycemic load is more efficient in preventing high blood glucose levels (3).
In addition, to understand the glycemic index and its relation to diabetes, you can read the article glycemic index and diabetes.
References
- https://pubmed.ncbi.nlm.nih.gov/2180214/
- https://pubmed.ncbi.nlm.nih.gov/17992183/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836142/
