The glycemic load attempts to resolve the questions that the glycemic index brings up concerning mixed foods, portion sizes and carbohydrate amounts in food. This system uses the standard serving size of a given food—an amount a person is more likely to eat-- and measures the impact the carbohydrate in the food has on blood sugar. The glycemic load is considered more reliable than the glycemic index since it takes into account the amount of carbohydrate in a standard portion size.
Glycemic load is calculated by multiplying its glycemic index by the amount of carbohydrate it contains then dividing the total amount by 100. So a fruit, such as watermelon, which has a high glycemic index, when analyzed using glycemic load is found to not to have a large impact on blood sugar. It is commonly known that watermelon contains mostly water and has only a small amount of carbohydrate.
Glycemic load, similar to the glycemic index, is broken up into three categories of low, medium and high. 1-10 is considered low, 11-19 is considered medium and 20 or more is considered high. Typically, the lower the glycemic load, the less impact the food will have on blood sugar levels. Using this scale, fruits and vegetables that are considered high glycemic index foods are no longer banned. When analyzed, they are found to be low glycemic load foods, with small amounts of carbohydrate and have little impact on blood sugar levels.
For more information, visit http://en.wikipedia.org/wiki/Glycemic_load, http://www.nutritiondata.com/help/estimated-glycemic-load, and http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/carbohydrates-and-the-glycemic-load/index.html.
