Hartmann Schedel

The index of body mass ( IMC ; in English, BMI : Body Mass Index ) makes it possible to evaluate the fat contents of a person, to determine her stoutness.

This index is calculated according to the size (in meters) and of the Masse (in kilograms). It is correctly interpretable only for a Adulte from 18 to 65 years. It constitutes an indication and intervenes in the calculation of the IMG.

Invented by Lambert Adolphe Jacques Quételet (1796-1874) - illustrates scientific Belgian, astronomer, mathematician and one of the founders of the modern statistics - this index is also called index of Quételet .

Interest of the IMC

WHO defined this index of body mass like the standard to evaluate the risks related to the overweight in the adult. It also defined standard intervals (thinness, normal index, overweight, obesity) while being based on the relation noted statistically between l'IMC and death rate. It is thus about a relative measurement which is not scientifically defined in a rigorous way.

The insurance companies states-uniennes use it in order to determine the risks of cardiovascular accident in their policy-holders starting from restricted data, and vary the premiums requested according to this criterion. The cardiovascular accidents are in any event rare before 65 years, and there exists many manners much more scientific to determine a risk: Cholestérolémie, Cardiac rhythm before and after effort, etc, all examinations that them known as companies cannot legally ask their customers.

This index is especially useful to highlight the increase in the risk factors. It does not have vocation to determine the value of the fatty mass precisely and even less muscular and osseous mass.

Interpretation of the IMC

|} The values of 18 and 25 constitute commonly allowed reference marks for a normal IMC (thus presenting an acceptable report/ratio of risk i.e. in the statistical standard). But it should be known however that mortality (statistical) starts to increase starting from a IMC by 21 (). This rise of mortality is an average all confused causes, but one particularly notes a rise of the deaths due to the cardiovascular diseases, cancers, the diabetes, the accidents progressively of the increase in the IMC.

Example of calculation

A person weighing 95 kg and measuring 1,81 m has a IMC:

IMC = \ frac {95 \; kg} {1,81 \; m \ times 1,81 \; m} \ approx 28,998 \; kg.m^ {- 2}

According to the preceding table, this person is in overweight.

A person weighing 48 kg and measuring 1,69 m has a IMC: $IMC = \ frac {48 \; kg} {1,69 \; m \ times 1,69 \; m} \ approx 16,8 \; kg.m^ {- 2}$

According to the preceding table, this person is too thin.

Attention should nevertheless be paid because this index of risk does not take into account the muscular proportion of mass nor of osseous mass. It is thus unsuited on certain populations and in particular the sportsmen, who find themselves then very often in overweight whereas their physical shape is often better than the average of the individuals.

It is also unsuited to the giant people or dwarf, like with the amputated people.

Other examples:

woman of 20 years, 1,70 m and 60 kg: IMC = 20,8;
woman of 40 years, 1,65 m and 55 kg: IMC = 20,2;
woman of 60 years, 1,60 m and 50 kg: IMC = 19,5;
man of 20 years, 1,80 m and 75 kg: IMC = 23,1;
man of 40 years, 1,75 m and 70 kg: IMC = 22,9;
man of 60 years, 1,70 m and 65 kg: IMC = 22,5.

Statistical data

France

Anecdote

In Spain, since 2005, the mannequins women whose l'IMC is lower than 18 are more authorized to take part in the processions. This measurement was taken to fight the risks of Anorexie in the easily influenceable young women. Indeed, l'OMS considers that a woman whose l'IMC is lower than 18 is not in good health. This measurement could be wide soon with the other countries of the European Union.

Table

Reference

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