Dieters who use the Glycemic Index of Foods as a guide to help select which carbohydrate-rich foods to eat and which to avoid generally succeed in shedding at least some of their excess weight. However, there is no single, definitive weight-loss diet based on the Glycemic Index but rather several that use the index for guidance. Because these diets vary in their specifics, the results they produce differ as well.
Glycemic Index
Originally developed in the early 1980s to help diabetics control their blood glucose levels, the Glycemic Index, or GI, gauges the speed at which various foods raise blood sugar levels, according to DiabetesNet.com. Although this is obviously invaluable information for anyone trying to manage his blood sugar levels, it also benefits dieters on weight-loss programs because it allows them to avoid foods that cause a sharp and sudden spike in blood glucose.
Significance for Weight Loss
Dieters who avoid foods that cause rapid surges in blood glucose also avoid the almost inevitable consequence of those surges, which is a precipitous decline in blood sugar levels that triggers hard-to-control cravings for more food. Steering clear of these insatiable cravings makes it far easier to stick to a weight-reduction program.
General Guidelines
When it was introduced, the GI covered less than 70 carbohydrate-rich foods. In the years since its introduction, hundreds of additional foods have been tested and their numbers added to the index, making it a fairly comprehensive guide to carbohydrates and their impact on blood sugar levels. The index rates foods on a scale of 0 to 100, according to Meri Raffetto, author of "The Glycemic Index Diet for Dummies." Foods that cause a rapid surge in blood sugar have high numbers, while those that have a more gradual effect on blood glucose are rated lower on the index. Dieters generally aim for foods at the lower end of the index, although higher-rated foods can provide a quick burst of energy on those rare occasions when that is needed.
Carbohydrates Only
The GI covers only carbohydrate-rich foods, which inevitably begs the question about its importance in overall diet, which includes protein and fat, the two other major categories of macronutrients. It is the role of carbohydrates in controlling blood sugar levels and thus appetite that makes the index so useful to dieters. Eating foods low on the index helps to avoid the blood sugar surges that so often result in overeating.
Sample GI Ratings
Foods that rank high on the GI include corn flakes cereal with a rating of 81 per cup; 1 oz. jelly beans, 78; three puffed rice cakes, 78; medium baked potato, 76; medium doughnut, 76; one slice of white bread, 73; and 2 tsp. granulated sugar, 68, according to Oregon State University's Linus Pauling Institute. At the other end of the scale, you'll find 1 oz. peanuts, 14; 1 oz. cashews, 22; 1 cup of dried kidney beans, boiled, 28; 8 oz. skim milk, 32; and 1 medium apple, 38.
References
- DiabetesNet.com: Food & Diet in Diabetes: Glycemic Index
- "The Glycemic Index Diet for Dummies"; Meri Raffetto; 2010
- Oregon State University, Linus Pauling Institute: Macronutrient Information Center: Glycemic Index and Glycemic Load
