Glycemic Indexes Do Not Depend on Glucose Absorption Speed

By Michel Montignac

Practically all of the definitions given by nutritionists (on the Web and elsewhere) for Glycemic Indexes are wrong.

In effect, they pretend that the advantage of a low GI carbohydrate is that it is absorbed more slowly and that blood glycaemia (blood sugar levels) hikes which are lower take longer time.

This is completely false!

A well-known French food industry brand even goes to the point of sustaining that eating its breakfast crackers will supply energy (glucose) for several hours as it is diffused slowly. This is so absurd that it is amazing that they can get away with even saying it.

For years, one of the most eminent diabetes experts in France, Professor Gérard Slama, has spoken from the DIETECOM (the annual nutrition symposium) tribune to insistently remind dietary professionals that the distinction between « fast sugars » and « slow sugars » is not based on physiological fact.

His struggle seems to be in vain since in France, like abroad, nutritionists and dietitians, continue to carelessly and abusively confuse "slow sugars" with low GI carbohydrates.

This is probably the reason why there has been no echo to the important study published in the "The American Journal of Clinical Nutrition " which has also shown that SCIENTIFICALLY THERE IS NO SUCH THING AS SLOW AND FAST SUGARS.

Said study (*) compares two Kellogg’s™ cereals:

-High GI Corn Flakes, on the one hand and
-Low GI All Bran (half the GI of Corn Flakes), on the other.

This test shows that glucose enters the bloodstream (intestinal absorption) takes just as long for Corn Flakes as it does for All Bran, that is, about 30 minutes.
High fiber content in All Bran does not slow down glucose passage, contrary to what nutritionists sustain.
The lapse of time required for glucose to pass into our bloodstream is the same for high and low IG carbohydrates.

Comparatively, Corn Flakes increase blood sugar levels twice as much as All Bran.

This study also shows that, after the corresponding insulinic responses, the glycemia curve in each case goes back to its initial stage after 180 minutes.

The food industry (with the complicity of certain nutritionists) pretends that a low-IG cereal diffuses glucose slowly and gradually, in approximately 4 hours. This is an outright lie which plays on people’s good faith and robs them of their right to knowledgeably choose what they eat.



"Different glycemic indexs of breakfast cereals are not due to glucose entry into blood but to glucose removal by tissue"

Schenk S. Am. J Clin Nutr. 2003; 78: 742-8

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