Understanding Glycemic Index and Glycemic Load

    Published: 06-16-2009
    Views: 30,402
    Dr. Russell Greenfield explains the Glycemic index, how it affects you and which foods are best for your health.

    Dr. Russ: Hi! I am Dr. Russ, and a member of Harris Teeter's Yourwellness team. Today I am going to discuss the terms Glycemic Index and Glycemic Load. And why understanding these terms may help you lead a healthier life. You may heard the terms Glycemic Index or Glycemic Load being mentioned when your doctors discuss nutrition and health. They are helpful dietary concepts, once we get down to basics. The Glycemic Index is used to classify foods based on how quickly they cause a rise in blood sugar upon being eaten. When high Glycemic Index foods are eaten there is a rapid rise in blood sugar followed by a significant release of insulin, causing blood sugar levels to fall, creating fatigue and hunger. Consistently eating high Glycemic Index foods may lessen your body's sensitivity to insulin over time leading to type-2 diabetes and other illnesses. Sugar and white bread are considered reference foods and have been assigned to Glycemic Index of 100, because they both cause a rapid rise in blood sugar levels after ingestion. All other foods are assigned a proportionately lower value from 1-99 based on how they affect blood sugar compared to sugar or white bread. Low Glycemic Index foods are digested more slowly resulting in gentle rise in blood sugar followed by a more moderate release of insulin. Thereby, helping to maintain consistent blood glucose levels and lessening fatigue and hunger. Glycemic Load takes the concept of Glycemic Index a step further offering a more accurate reflection of the impact eating a specific food has on your blood sugar and insulin levels. The Glycemic Load takes into account the relative amount of carbohydrate the food contains in an average survey. As an example, watermelon has a Glycemic Index of 72 which is pretty high but it's mostly made up of water and contains relatively little carbohydrate. So its Glycemic Load is only between 4 and 7. Now your blood sugar may go up rapidly after eating watermelon, but it shouldn't go up very much, since there is not much carbohydrate present in watermelon to be converted into sugar in the first place. On the other hand, half a bagel has a Glycemic Index similar to watermelon at 72 but a much higher Glycemic Load of almost 26. Thus, a bigger sugar load for your body.

    There are many reference lists that to tell the Glycemic Index and Glycemic Load of your favorite foods. And both Glycemic Index and Glycemic Load are helpful guides when choosing healthy carbohydrates, but you can't determine whether or not a food is healthy for you based solely on these numbers. They are useful concepts, but the quality and concentration of nutrients found within a given food have to be factored in as well. I hope this helps clear up any confusion around Glycemic Index and Glycemic Load for you. Be well.