This idea perplexes me. Here's a quote from Wikipedia that I am having trouble grasping: "Rather than relying on blood glucose levels, the Insulin Index is based upon the insulin response to various foods, and seems to be more promising than either the Glycemic Index or the Glycemic Load. The primary reason for this is that certain foods (e.g., lean meats and proteins) seem to cause an insulin response despite there being no carbohydrates present. Additionally, other foods seem to cause a disproportinate insulin reaction for its carbohydrate load."