Glycemic Index is a term used to measure the speed at which carbohydrates break down in the digestive system to form glucose (sugar). Glucose is the body’s source of energy-it feeds the muscles, brain and other organs. Sugar has a glycemic index of 100 and all foods are indexed against that number. So foods that are quickly digested tend to have a higher glycemic index and foods that are digested more slowly tend to have a lower glycemic index. Fats slow down the absorption of foods and therefore by adding olive oil to foods the glycemic index will go down.