25 September, 2010


If a person consumes 50% of his or her calories from carbohydrates, the glycemic index can enable him or her to consume the same number of calories and have lower, more stable glucose and insulin levels. The use of the glycemic index, however, is limited by several factors:

The glycemic index does not take into account other factors besides glycemic response, such as insulin response, which is measured by the insulin index and can be more appropriate in representing the effects from some food contents other than carbohydrates.

The glycemic index is significantly altered by the type of food, its ripeness, processing, the length of storage, cooking methods, and its variety (white potatoes are a notable example, ranging from moderate to very high GI even within the same variety

The glycemic response is different from one person to another, and even in the same person from day to day, depending on blood glucose levels, insulin resistance, and other factors.

The number of grams of carbohydrate impacts blood sugar levels more than the glycemic index. Lowering glycemic index leads to small improvements in the blood sugar level, but consuming fewer calories, losing weight, and carbohydrate counting would benefit the blood sugar level more.Carbohydrate impacts glucose levels most profoundly, and two foods with the same carbohydrate content are, in general, comparable in their effects on blood sugar. A food with a low glycemic index may have a high carbohydrate content or vice versa; this can be accounted for with the glycemic load. Consuming carbohydrates with a low glycemic index and calculating carbohydrate intake would produce the most stable blood sugar levels.

Most of the values on the glycemic index do not show the impact on glucose levels after two hours. Some diabetics may still have elevated levels after four hours.

The GI of foods is determined under experimental conditions after an overnight fast, and might not apply to foods consumed later during the day because glycemic response is strongly influenced by the composition of the previous meal, particularly when meals are consumed within an interval of few hours. Indeed, it has been shown that a high-GI breakfast cereal (GI = 124) elicited a lower increase in blood glucose concentrations at lunch than at breakfast. Also, the difference in glycemic responses induced by the low- and the high-GI breakfast cereals at lunch were lower than that predicted by the large difference in their GI, which was determined at breakfast.

1 comment :

  1. Don't know how far it can be practically used in day-today life. Probably has more value in research.


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