The glycemic index is a measure of the effects of carbohydrates on blood sugar levels. It's a ranking of foods based on their immediate effect on blood glucose (blood sugar) levels.
The glycemic index or glycaemic index (GI) is a number associated with a particular type of food that indicates the food's effect on a person's blood glucose (blood sugar) level. A value of 100 represents the standard, an equivalent amount of pure glucose. The glycemic index is usually applied in the context of the quantity of the food and the amount of carbohydrate in the food that is actually consumed. The glycemic response is different from one person to another, and also in the same person from day to day, depending on blood glucose levels, insulin resistance, and other factors.
"The glycemic index was a concept that was introduced by Dr. David Jenkins out of the University of Toronto," says Sarah Ware, a Registered Dietitian, Certified Diabetes Educator and HealthChoices.ca partner. "It's a concept that categorizes food on how quickly it causes a rise in blood sugar once ingested; it categorizes food whether they are high glycemic or low glycemic."
It's not - the glycemic index is just a way to understand how a food will affect blood sugar. Some starchy foods have a high glycemic index, which can cause high blood sugar levels after meals.
High glycemic foods include baked potatoes and instant rice. Other foods are non-starchy, such as many vegetables, fruits and legumes, and can help prevent high blood sugar after meals.
"It's interesting to note that food like white bread or potatoes actually cause a faster blood sugar rise than a food like regular table sugar," says Ware. "So when you're choosing your meals, for example if you wanted rice for dinner try to choose wild rice over white, and when it comes to fruit choose blueberries over watermelon."
The glycemic index (GI) can help diabetic patients manage blood glucose.
A recent study done by Bajorek S.A. and Morello C.M. at Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California in San Diego reports that people who took psyllium fiber supplements and followed a low glycemic index diet improved glycemic risk factors.
Many people use the glycemic index to help them select foods for meal planning, but it can be hard to follow a glycemic index diet on your own to manage your diabetes.
"If somebody has more questions about the glycemic index they should speak with a dietitian, Certified Diabetes Educator or a diabetes specialist," says Ware.