Limitations Of Using The Glycemic Index To Make Food Choices

Some people pay particular attention to the glycemic index of foods in planning their diets. However, there are limitations to what the GI can tell you about a food.

This article, which was first written and published on another website in 2008, discusses areas which the GI does not tell you about foods.

Glycemic Index of Foods – limitations of the value

The glycemic index of foods is used to give a gauge of the rate at which consumption of a certain food would cause glucose levels in the blood to rise. Click here for an explanation of the glycemic index and how it works.

In general, a low glycemic index (GI) value is taken to imply a higher quality of carbohydrates, and low glycemic index diets and foods are associated with numerous health benefits for us. (click here for a list of low glycemic foods)

However, there are a few limitations and shortcomings of the glycemic index, and these are briefly described below.

Firstly, the glycemic index is limited to measuring the rate of release of glucose into the bloodstream, and does not in any other way measure the quality of foods in terms of nutritional value. There are healthy high-GI foods, and also unhealthy low-GI foods. While the glycemic index guides our food choices, over-reliance on the glycemic index of foods to plan one’s diet could actually compromise the need to obtain certain essential nutrients in one’s diet.

In addition, glycemic response to a certain food can vary from person to person, and can even be different in the same person when the food is consumed at different times of the day.

Glycemic response to a certain food also depends on the specific piece of food being eaten, for example its particular species, how ripe it is, how long it has been stored, how it was prepared and cooked, what flavorings and condiments were added to it, etc.

Further, the glycemic index takes into account glycemic response, but fails to account for other reactions of the body, for example insulin response. Although glycemic response and insulin response are related, they are not always fully correlated.

Another limitation of the glycemic index of foods is that it is limited only to glucose, without taking into account the effect of other types of sugars on the body, for example fructose. Although other types of sugars may not cause the same spurts in insulin levels which glucose does, they have other negative effects on a person’s health.

Click here for a listing of low glycemic foods, or click here for some high glycemic foods to avoid or cut down on. For a general glycemic index listing of foods, click here instead.