Limits of GI values

The glycemic index doesn't consider how much of a food you are likely to eat during a meal. For example, you likely wouldn't eat a whole medium-sized cantaloupe at once.

To focus on this problem, researchers developed the idea of glycemic load (GL). This number shows the effect on blood sugar levels when you eat a common portion of the food. For example, you might eat one-third of a medium-sized cantaloupe during one meal. The GL value for that much cantaloupe is around 11 or lower.

Sydney University's table of GI values also includes GL values. The GL values are divided into:

• Low GL: 1 to 10
• Medium GL: 11 to 19
• High GL: 20 or more