The GI (Glycemic Index) Diet

The GI (Glycemic Index) Diet

The Low Glycemic Index Diet was developed by Dr. David J. Jenkins, a professor of nutrition at the University of Toronto and later turned into a successful line of diet books by author and former president of the Heart and Stroke Foundation of Ontario, Rick Gallop. According to the publishing company, Virgin Books, the G.I. Diet has sold over two million copies.

G.I. stands for Glycemic Index, a medical term used to measure the speed at which carbohydrates break down in the digestive system to form glucose. Glucose is the body's source of energy - it is the fuel that feeds your brain, muscles, and other organs. Glucose is set at 100, and all foods are indexed against that number. So foods that are quickly digested have a high G.I. and foods that are digested more slowly have a lower G.I.

In spite of the common belief that table sugar contributes to the development of diabetes, it has medium (55-69) GI that produces lower blood glucose levels than the equal amount of calories obtained from starch and some other carbohydrates. Leading international diabetes associations (e.g. Canadian Diabetes Association) recommends that table sugar be actually part of the diabetes diet.

Examples Of G.I. Ratings

High G.I.   Low G.I.*  


Rating Foods Rating
Glucose 100 Grapefruit Juice 48
Baguette 95 All Bran 43
Cornflakes 84 Oatmeal 42
Rice Cakes 82 Spaghetti 41


    * Any food rating less than 55 in the G.I. is considered low

According to the Low G.I. Diet, when you eat high G.I. foods, such as corn flakes, your body rapidly converts them into glucose, which dissolves in your bloodstream, spiking your blood sugar level and giving you that familiar sugar rush or high. When you eat a low G.I. food, such as oatmeal, it will break down more slowly and deliver the glucose into the bloodstream at a slower but steady rate.