The amount of carbohydrate in a food significantly influences blood sugar levels. This is why the portion size used to measure the glycemic index (GI) is so important. Studies show that blood sugar response, measured as the area under the curve (AUC), increases steadily as carbohydrate intake rises from 0 to 50 grams. However, beyond 50 grams, the increase slows down and begins to level off (Wolever, 2003). This is why 50 grams of carbohydrate is the standard amount used for GI testing. Using smaller portions can result in a weaker blood sugar response, which might make the GI appear artificially low.

Understanding the Role of Carbohydrate Amount and Availability in Glycemic Index (GI)

Interesting News . Nov 21, 2024

The amount of carbohydrate in a food significantly influences blood sugar levels. This is why the portion size used to measure the glycemic index (GI) is so important. Studies show that blood sugar response, measured as the area under the curve (AUC), increases steadily as carbohydrate intake rises from 0 to 50 grams. However, beyond 50 grams, the increase slows down and begins to level off (Wolever, 2003). This is why 50 grams of carbohydrate is the standard amount used for GI testing. Using smaller portions can result in a weaker blood sugar response, which might make the GI appear artificially low.

Equally important is the availability of the carbohydrate—that is, how much of it can be digested and absorbed. To ensure accurate GI measurements, the test must include 50 grams of absorbable carbohydrates. This excludes components like dietary fiber, resistant starch, and other forms of carbohydrates that are not broken down or absorbed in the small intestine (Wolever, 2003).

While this approach seems straightforward, it is challenging in practice. Different laboratories often use varying definitions and methods to measure carbohydrate availability. This variability can make it difficult to standardize GI values. Additionally, in everyday eating, many foods contain fiber, resistant starch, and other components that lower carbohydrate availability, which can limit how applicable GI measurements are to real-life diets.

At Food Research Lab (FRL), we specialize in providing comprehensive Glycemic Index (GI) testing services that empower food and beverage manufacturers to validate their product’s impact on blood sugar. Our testing follows internationally recognized protocols and is conducted at our ISO-certified clinical research facility, ensuring accuracy, reliability, and global compliance.