The glycemic index ranks foods that contain carbohydrates based on how much of an effect they have on blood glucose levels. High-glycemic index foods have values of 70 or above, according to the Home of the Glycemic Index at the University of Sydney. Low-glycemic index foods have glycemic index values of 55 or less. The lower the glycemic index value, the less of an effect the food has on blood glucose levels. Diabetics use this ranking tool to select foods that will not result in sudden increases in blood sugar.
Fruits
Fruits contain vitamins, minerals and fiber, which means they belong in a well-balanced diet. Fruits also contain sugars, making it necessary for diabetics to use caution when adding fruits to meals or eating them as snacks. Several fruits have glycemic index values of 55 or less, according to The World's Healthiest Foods. These fruits include raw apples, dried apricots, grapefruit, prunes, dried apples, plums and pears.
Vegetables
Vegetables have several features that make them essential for good health. Some vegetables contain compounds that have cancer prevention properties. When selecting vegetables, diabetics should distinguish between starchy and nonstarchy vegetables. Most starchy vegetables have a glycemic index above 55. Yams are an exception, with a an average glycemic index of 37 as reported by Kaye Foster-Powell, co-author of "The Low GI Diet Cookbook" and "The New Glucose Revolution Pocket Guide to Losing Weight." Nonstarchy vegetables have lower glycemic index values, making them better for controlling blood glucose levels. These foods have glycemic index values ranging from 15 to 50, according to The World's Healthiest Foods. Low-glycemic index vegetable options include turnip greens, spinach, lettuce, zucchini, artichokes, cucumbers, broccoli, eggplant, brussels sprouts, tomatoes, celery, onions, asparagus and bell peppers.
Whole-Grain Products
White bread, white bagels and other products made with refined ingredients have high glycemic index values. Foster-Powell reports that one white bagel has a glycemic index of 72. Some products made with whole grains have lower glycemic index values, reducing their effect on blood glucose. One slice of coarse wheat-kernel bread made with white-wheat flour and 80 percent intact wheat kernels has a glycemic index of 52. One slice of whole-meal rye bread has a glycemic index of 41.
Dairy Products
Dairy products contain lactose, a form of sugar, but some have low glycemic index values. Whole milk has a glycemic index value of 27, according to professors Jerry Mayo and Len Kravitz of the University of New Mexico. Mayo and Kravitz explain that a low glycemic index value does not necessarily mean a food is healthier than other foods. They use the example of whole milk versus skim milk. While whole-fat milk has a glycemic index of 27, low-fat milk has a glycemic index of 32. Skim milk has less fat and fewer calories, but it also has more of an effect on blood glucose levels.
References
- University of Sydney: Home of the Glycemic Index
- The World's Healthiest Foods: What is the Glycemic Index
- "American Journal of Clinical Nutrition"; International Table of Glycemic Index and Glycemic Load Values; Foster-Powell, K, et al.; 2002
- University of New Mexico: Glycemic Index: Weight Loss Sham or Sensation?
