Monitoring the glycemic index of foods that you eat is one way to help control your blood glucose levels. The glycemic index of a food is related to the kinds of carbohydrates it has, and high glycemic index foods may not be good for people who have diabetes or are concerned about developing type 2 diabetes.
Glycemic Index Determination
The glycemic index of a food is measured by giving 50 g of carbohydrate-worth of the test food to a volunteer and then measuring the changes in the volunteer's blood glucose levels over time, the Linus Pauling Institute states. The rise in the blood glucose levels are compared to a "control" food, such as white bread or glucose to determine the glycemic index of the test food. The more the volunteer's blood glucose level changes, the higher the glycemic index for the test food.
High Glycemic Index Foods
Foods that have a high glycemic index have carbohydrates which are rapidly broken down by the digestive tract, causing a rapid increase in blood glucose levels. Foods with a glycemic index above 70 are considered to be high glycemic index foods, the American Diabetes Association notes. For example, white bread, bagels and many cereals, including corn flakes and instant oatmeal. Russet potatoes, pumpkins, shortgrain white rice, rice pasta, pretzels, saltines, pineapple and melons also have high glycemic index values.
Glycemic Index and Type 2 Diabetes
Avoiding foods that have a high glycemic index can lower your risk of developing type 2 diabetes. Foods with a high glycemic index cause your blood glucose levels to rise, triggering the secretion of insulin by your pancreas. Excessive insulin secretion is partly responsible for type 2 diabetes. Avoiding high glycemic index foods can also make it easier for you to control your blood glucose levels if you have type 2 diabetes.
Considerations
Although avoiding foods with a high glycemic index can aid in blood glucose control, there are some flaws in planning a diet based on the glycemic index. For one thing, the glycemic index only measures the effects of carbohydrates and ignores other nutrients such as saturated fat and cholesterol, which should be limited in a diet. Also, the more a food is cooked, chopped or ground, the higher its glycemic index; the glycemic index of foods does not take that into account.
