The Glycemic Index has been around for over 20 years. It ranks carbohydrate foods on how they affect the body’s blood glucose levels.  Your body converts all carbohydrates into sugar molecules that are burned or stored.  The faster carbohydrates are broken down by your digestive system, the quicker blood sugar goes up and the higher the GI.  When carbohydrate is eaten, it raises your blood glucose levels, which in turn trigger the release of insulin to bring the levels back down to “normal”.  

 The Glycemic Index has been getting renewed media attention as an easy way to control appetite, manage weight and blood glucose levels.  The major appeal of using the Glycemic Index to group foods is to make meal planning easier, especially for individuals with diabetes.  Great theory, but research indicates that it serves none of these functions, instead, it has been used as a dieting “gimmick” to sell books and magazine articles.   

A food can have different Glycemic Index values as a result of ripeness, how it is cooked and how it has been processed.  The GI of a potato grown somewhere in Australia is different than the GI of a potato grown in the state of Idaho in the United States. The GI of the Idaho potato is different than the GI of a potato grown in Pennsylvania.  If you could find the GI of the type of potato you eat daily (which is almost impossible) the GI of the potato eaten alone is different than when it is eaten with another food.  Research has also shown that the GI of a food varies significantly from person to person.  For some folks, it can even vary from day to day.  It has been found that glucose levels after a regular meal peak at about the same time regardless of carbohydrate source.  This is most likely because of the different types of carbohydrates eaten at the same time.  The body’s insulin response to a specific food is not directly related to the carbohydrate content  or GI value of the food. 

The Glycemic Index should not be considered a guide for healthy food choices.  Many foods can have a low GI, such as candy, soft drinks and high fat foods, but have questionable nutritional value.  For diabetics, monitoring total grams of carbohydrate is still the best strategy.  At this time, research does not support the use of the Glycemic Index for healthy meal planning.  For more information concerning the Glycemic Index contact the dietitians of Hill Nutrition Associates, Inc. at 772-220-8058.