- The Glycemic Index is a ranking of foods based on how quickly and how greatly they cause increases in blood sugar after they have been eaten. Each food is given a specific number ranging from 0 to 100. Lower numbers are better because these are foods which are digested more slowly and cause gradual increases in blood sugar over a longer period of time. A fruit-flavored roll-up, for example, has a glycemic index value of 99 which means it causes a fast increase in blood sugar numbers. Vegetarian lasagna, on the other hand, has a value of only 20.
- Back in the 1980 at the University of Toronto, Dr. David J. Jenkins and his colleagues created the Glycemic index as a way to determine the foods to recommend for diabetic patients. Because foods at the lowest end of the spectrum require less insulin to be processed by the body, they are better choices for people whose pancreas cannot produce sufficient levels of insulin. The rankings for each of the foods were determined by checking the insulin response to them in ten different healthy people. The body's response for each food is compared to the results for glucose which is valued at 100 on the GI.
- If you are trying to control your weight or stick to a diabetic diet, the Glycemic Index can give you some idea of which foods to include in your meals and which to avoid. For example, any food with a GI value of less than 55 is considered to be at the low end of the spectrum. These foods include pasta, milk, eggs, fruits, and the majority of vegetables. Additionally, you can use the index to find foods to have available in case your blood sugar levels drop or after you have exercised. Foods considered high on the Glycemic Index include potatoes, white rice, and any food containing high levels of sugar, such as non-diet soda.
- Following a diet consisting of foods low on the Glycemic Index has been shown to have a number of health advantages, even for people who are not diabetic or overweight. Recent studies have shown that the consumption of foods high on the index can cause damage to the heart and blood vessels which can increase your chances of developing heart disease. Low GI foods have been shown effective in weight loss programs and in reducing the risk of Type 2 diabetes.
- A related concept to the Glycemic index is known as the Glycemic Load (GL). This concept was created by the University of Sydney on the idea that portion size, as well as the GI value of a food, was important. The idea is that eating a large quantity of low GI value foods could be as detrimental, too. The GL value for food is determined by multiplying the grams of carbs in a single serving by the GI value then dividing by 100. For example, a banana has a GL value of 10. While GL is intended to answer some of the criticisms against the Glycemic Index, eating a diet of low GL foods has not been proven to have much impact on weight loss.
