Glycemic Index and Diabetes
The glycemic index (GI) measures how a carbohydrate-containing food raises blood glucose. Foods are ranked based on how they compare to a reference food — either glucose or white bread. A food with a high GI raises blood glucose more than a food with a medium or low GI. There is no GI fo meats and fats as not containing carbohydrate.
Low GI Foods (55 or less)
- 100% stone-ground whole wheat or pumpernickel bread
- Oatmeal (rolled or steel-cut), oat bran, muesli
- Pasta, converted rice, barley, bulgar
- Sweet potato, corn, yam, lima/butter beans, peas, legumes and lentils
- Most fruits, non-starchy vegetables and carrots
Medium GI (56-69)
- Whole wheat, rye and pita bread
- Quick oats
- Brown, wild or basmati rice, couscous
High GI (70 or more)
- White bread or bagel
- Corn flakes, puffed rice, bran flakes, instant oatmeal
- Shortgrain white rice, rice pasta, macaroni and cheese from mix
- Russet potato, pumpkin
- Pretzels, rice cakes, popcorn, saltine crackers
melons and pineapple
Factors affecting the GI of Food
Fat and fiber tend to lower the GI of a food. As a general rule, the more cooked or processed a food, the higher the GI but it is not always true.
Other factors affecting the GI of a food
- Ripeness and storage time — the more ripe a fruit or vegetable is, the higher the GI
- Processing — juice has a higher GI than whole fruit; mashed potato has a higher GI than a whole baked potato, stone ground whole wheat bread has a lower GI than whole wheat bread
- Cooking method — the time of cooking (al dente pasta having a lower GI than soft-cooked pasta)
- Variety — converted long-grain white rice has a lower GI than brown rice but short-grain white rice has a higher GI than brown rice.
Other factors to be considered
The GI value represents the type of carbohydrate in a food but without indication of the amount of carbohydrate typically eaten. Portion sizes are still relevant for managing blood glucose and for losing or maintaining weight.
The GI of a food is different when eaten alone than it is when combined with other foods. When eating a high GI food, combine it with other low GI foods balance out the effect on blood glucose levels. Many nutritious foods have a higher GI than foods with little nutritional value.
The glycemic index compares the potential of foods containing the same amount of carbohydrate to raise blood glucose. However, the amount of carbohydrate consumed also affects blood glucose levels and insulin responses.
The glycemic load of a food is calculated by multiplying the glycemic index by the amount of carbohydrate in grams provided by a food and dividing the total by 100. Dietary glycemic load is the sum of the glycemic loads for all foods consumed in the diet. The concept of glycemic load was developed by scientists to simultaneously describe the quality (glycemic index) and quantity of carbohydrate in a meal or diet.
No one diet or meal plan serve everyone with diabetes. It is of paramount importance to follow a meal plan specifically tailored to personal preferences and lifestyle and helps achieving goals for blood glucose, cholesterol and triglycerides levels, blood pressure, and weight management.
Diabetes: What is the Glycemic Index?
Understanding Glycemic Index and Glycemic Load
Low Glycemic Index Fruits and Vegetables for Blood Sugar Control
Hunger and the Glycemic Index