The BMI (Body Mass Index) was invented in the 19th century by a Belgian scientist named Adolphe Quetelet (1) .
This invention now makes it possible to objectively control the state of corpulence of an adult woman. It is a calculation based on a principle of proportionality between height and weight. The interpretation of the result is done in accordance with the principles of the World Health Organization.
Good to know : if you want to directly calculate your BMI, click on this link . To learn more about BMI in a very general way, you can
read our generalist file on the subject (common to men and women).
If you simply want to learn more about the particularities of BMI in women, you can continue reading this file.
PARTICULARITIES OF BMI IN WOMEN
The very first thing that is important to dwell on is the formula for calculating the Body Mass Index. This formula is strictly identical for men and women . When calculating the BMI, it is therefore not useful to specify the sex of the person, unless the person in question is under 18, in which case it is the BMI in children who s applies (2) (and which is done according to sex).
However, even if the calculation of BMI in adults is done in the same way for men and women, the effects of weight gain are different for one or the other of the two sexes.
This is the reason why this page contains information intended to provide clarification on the female points of the BMI calculation.
PARTICULARITY OF WEIGHT GAIN IN WOMEN
In women, weight gain, compared to men, may be more substantial. Indeed, taking the contraceptive pill or pregnancy can lead to significant weight gain. Fat is gaining ground and it is sometimes very difficult to lose a lot of weight after pregnancy.
Thus, a BMI greater than 30 affects more women than men (15.1% against 13.9%).
However, there are more overweight men than women (38% vs. 26%).
Women prefer snacking over men (even without being pregnant). They accumulate fat mainly in the lower body. Thus, the hips , thighs and buttocks are mainly affected by the increase in fat. Also the stomach . Women particularly suffer from this weight gain and no longer feel good about themselves, putting their assets aside under mountains of thick clothes. This is a problem that generally affects men less.
Weight gain is greater but less surprising in women due to many hormonal reasons.
WHY THE SAME BMI CALCULATION FOR WOMEN AND MEN?
It makes sense to ask this question. Indeed, since weight gain is different for women, and since women naturally store more fat than men (who have more muscles), then why is the calculation identical?
What should be remembered about this indicator and its reliability is that it is above all a simplified calculation tool . This is the reason why the calculation does not differ between men and women. The BMI, the use of which is recommended by the WHO (World Health Organization), has its inaccuracies (for example the lack of differentiation between men and women), but it also has its advantages: it is generally reliable and above all very simple to implement.
» The BMI is a sure value to calculate your weight and to know if you present abnormal risks in front of certain diseases.
For an equal BMI, for example for an index of 30, it is (generally) better to be a man than to be a woman. Indeed a visual study (3) was carried out with simple diagrams representing different men and different women, in different states of corpulence. The objective was to determine, visually, in which category ( normal corpulence , overweight , obesity , etc.) the men presented were located, and the same for the women.
The conclusions of this study are unequivocal: for men perceived obesity (ie visually) was far from obesity in the sense of BMI. Judgment of obesity was only made from a BMI threshold set (visually) at 31.5. On the other hand, for women, obesity perceived visually corresponded (almost) to obesity in terms of BMI, with a BMI threshold set (visually) at 29.9.
Clearly, and on average, a woman with a BMI of 30.5 is obese according to the interpretation of the WHO, and is seen “visually” as obese . But a man with a BMI of 30.5, even if he is obese according to the WHO definition, is not “visually” seen as obese.
Obesity perceived visually therefore displays a difference, still according to this study carried out in 1983 (3) , of 1.6 kg/m2. This may suggest that the calculation of BMI is biased in men, and that it is less so in women.