Sort of. The glycemic index is not really useful because it is based on arbitrary quantities of food. Glycemic load was created to be useful to people, as it is based on reasonable quantities people would eat. Like GI says watermelon is bad because its calories come from sugar. But it is based on eating 100g of carbs from watermelon. That's a huge amount of watermelon, which is mostly water. GL shows watermelon is fine, because you only eat 10g of carbs from it in a normal serving.