Index glycemic

The glycemic index is a criterion of classification of the Glucides based on their effects on the Glycémie (rate of glucose in blood) during the two hours following their ingestion. It makes it possible to compare the glycémiant capacity of each food, measured directly during digestion. The index glycemic was invented by the team of David J. Jenkins with the Université of Toronto in 1981.

The food having an index glycemic lower than 55 is known as slow sugars , those whose index glycemic is higher than 70 are called fast sugars .

Calculation of the index glycemic of a food

Value of reference and conversions

The index glycemic of a food is given compared to a reference.

In Europe, one takes for reference the Glucose to which one allots the index 100 .
With the the United States of America, the white Pain is often selected like reference (index 100 ).

To pass from a measurement taking for reference the white bread in the system having for reference glucose, it is necessary to multiply this one by 0,7 .

Method of the triangle

In order to calculate the index glycemic of a food, one often uses the method known as triangle , which consists in comparing the surface under the curve representing the glycemia according to the time of known as food, with that of the reference. In Europe, one thus uses the formula:

$I_g = \ frac {S_a} {S_g} * 100$

$I_g$ : Index glycemic of food or sugar considered
$S_a$ : Surface under the curve glycémie.temps food or sugar considered.
$S_g$ : Surface under the curve glycémie.temps reference (glucose).

By the term surface under the curve one indicates the following phenomenon: i.e. the surface of the triangle formed by the axis of the normal value of the glycemia (1g.L^-1) and by the curve.

Limits of this system

The system of the index glycemic allows, for example, with the people diabetics to supervise their food, to envisage this one according to their needs. However, the figures indexed in the tables are not always representative of reality. There exist many factors varying the glycémiant capacity of a food.

Causes of the variations of being able glycémiant

the physical status of the food (solid or Liquid): the same food in these two forms does not have the same index glycemic.
mode of Cooking: The way in which the food was cooked (the temperature, duration, possible fat contents) can vary to be able to them glycémiant. (the mashed potatoes of potatoes for example have a IG approximately 70 whereas the potatoes cooked with the Four can have a IG going up to 90)
mode of Consommation: The way in which are consumed food also made vary to be able to them glycémiant. In a general way, the sugars consumed during a meal, in particular in the presence of Vegetable S greens, present an action on the glycemia weaker than the tabular values.

See too

http://www.montignac.com/fr/ig_pionnier.php The pioneer of the indices glycemic (IG)

External bonds

Montignac Method: Glycemic IG
Table of the indices of principal food - by group and index glycemic
dynamic Index glycemic of the food
Article: Mode: the impact of the index glycemic of the food
International counts off glycemic been worth (GI) indices and glycemic (GL) load: 2002

Random links: