Carbohydrates are your body's main energy source, but not all carbs are the same. Vegetables and whole grains digest slowly, providing a steady release of energy into your bloodstream. In contrast, sugary snacks and refined grains cause intense energy spikes and crashes, which can lead to bingeing and overeating. The Glycemic Index, or GI, determines which carbs are high or low glycemic, assisting you with blood-sugar management and weight control.
The Glycemic Index
Researchers at the School of Molecular and Microbial Biosciences at the University of Sydney developed the Glycemic Index. This dietary ranking system rates carbohydrate-containing foods on a numerical scale of 0 to 100, depending on how quickly you digest them and how quickly they are converted to glucose in your bloodstream. A GI ranking of less than 55 rates as "low glycemic," while a GI number of more than 55 is "high glycemic." Protein and fats such as meat, fish, poultry, nuts and seeds have no ratings, because their effect on blood glucose is negligible.
High-glycemic Foods
High-GI foods include many refined grains, cereals and sugary snacks -- and also a few starchy vegetables. White bread and rolls, bagels and white rice are all high-GI foods. Corn and rice breakfast cereals -- such as corn flakes and popped rice cereal -- receive high ratings, as do many refined crackers. Among bakery goods, a single scone from a mix has a GI rating of 92. The vegetable with the highest GI score is the white potato, with a simple baked potato scoring 93.
Low-glycemic Foods
Many vegetables have a GI of less than 20, including asparagus, bell peppers, broccoli, carrots, cauliflower, cucumber, eggplant, spinach and tomatoes, among others. Most beans and legumes are also low glycemic, with soybeans rating the lowest at 14. Apples, apricots, cherries, oranges, peaches and pears are all low-glycemic fruits. Grains that have a low GI rating include barley, brown rice and bulgur. Other low GI foods include low-fat yogurt and rye and pumpernickel breads.
Considerations
According to the University of Sydney, diabetics and others needing to manage blood glucose may include some high-GI foods in their diets as long as low-GI choices are also part of their meals. The GI research team recommends consuming at least one low-GI carbohydrate per meal to manage blood sugar and keeping a healthy balance of carbs, protein and fat in your diet. Use the GI to choose the best carbohydrate choices and spread them out over the course of a day.
References
- "The Encyclopedia of Healing Foods"; Michael Murray, ND, and Joseph Pizzorno, ND; 2005
- The Glycemic Index: Home of the Glycemic Index
- Linus Pauling Institute; Glycemic Index and Glycemic Load; Jane Higdon, Ph.D.; December 2005
