The glycemic index, or GI, is a useful tool for people with diabetes to manage their diet for better blood sugar control. The glycemic index measures how much a food containing carbohydrates may increase blood sugar levels. Foods with a high glycemic index are digested and absorbed quickly which causes a rapid increase in blood sugar levels.  In comparison, foods with a low GI value are digested slowly causing a slower increase in blood sugar levels.  Low GI foods are typically rich in fiber and protein but may also be high in fat, saturated fat and calories.

This index is based on the weight of the food, 50 grams, and not the portion size. For example, 50 grams is about one cup of cooked rice but is 4 cups of cooked beets. Portion control is important for managing blood sugar and weight, regardless of the GI value of the food.  

Glycemic Index is not related to the nutrition quality of the food. Chocolate and carrots have the same GI value of 49, which is considered a low GI food, but obviously carrots are much higher in nutrient value than chocolate. Keep in mind that the GI is based on a single food being consumed alone on an empty stomach but usually we eat foods together in a meal. One way to use the GI system is to combine high-GI foods with low-GI foods to balance the meal or try to select more medium and low GI foods.  

Several factors can influence the GI value of foods. Fruit juice has a higher level than fruit since the fruit has fiber to lower the glycemic index. The ripeness of the fruit increases the GI value, because the fruit creates more sugar naturally, as it ripens. The more processed a food, generally the higher the GI value. For example, mashed potatoes have a higher GI value than a baked potato.  

There is no one diet or meal plan that works for everyone with diabetes.  A good foundation is to select high-fiber foods, such as whole grains, legumes, fruits and vegetables, balanced with meat, dairy and healthy fats. Choose more foods in their natural state, and less processed foods. 

Meal plans should be individualized to meet personal food preferences and lifestyle to control blood sugar, cholesterol and triglyceride levels and maintain a healthy weight. A registered dietitian can develop a personalized meal plan that works for you. To find a registered dietitian in your area, go to https://www.eatright.org/find-a-nutrition-expert .

The Glycemic Index should not be the only guide to determine food choices but is another tool to use in the meal planning process. For more information on the Glycemic Index, go to the American Diabetes Association at www.diabetes.org.