90% of the population is obese, but most don't know it

Find out the truth about obesity: BMI doesn't tell the whole story!

1. World Health Organization and Obesity

The World Health Organization (WHO) defines obesity as “a condition in which the percentage of body fat has increased to such an extent that health and well-being are compromised and, due to the alarming increase in the prevalence, has declared as a "global epidemic".

The high prevalence of obesity is a global public health problem due to its association with various diseases and shortened lifespan.

It arises as a result of a complex interaction of genetic factors, lifestyle and especially eating habits.

Because of the endocrine and inflammatory role of fat tissue, it is necessary to classify the condition of obesity on the basis of body fat composition and distribution, rather than simply on body weight gain.

2. Body mass index, what it is and how it is used

Therefore, the body mass index "BMI" in English "BMI", a ratio of weight and height squared (kg/m 2 ) of a subject, used to easily approximate body fat percentage and stratify people into categories, leads to a big mistake, misclassification, and especially to underestimation of obesity.

However, due to its ease of use, it is used every time you try to classify a specific population.

In fact, the obsolete BMI formula developed nearly 200 years ago by Quetelet does not measure fat, it is simply an inaccurate mathematical estimate[ 12 - 14 ].

Its popularity stems in part from its convenience, safety, and minimal cost, and its use is widespread, despite the fact that BMI ignores several important factors influencing adiposity.

Furthermore, the error in the diagnosis of obesity generates a false belief in people that they are not at risk of developing diseases, thus becoming an additional risk factor.

Especially those with a low amount of muscle mass and an excess of lean mass, defined as "fake thin" can easily be classified as obese with a normal BMI.

The BMI formula is only an arithmetic approximation for the relative amount of adiposity and is used to predict and assess disease risk in epidemiological studies, thus acting only as a population-level indicator of obesity.

However, according to a WHO expert committee, "there is no agreement on the cutoff points for the PBF that constitutes obesity."

3. BMI vs Body Fat Percentage

Current research suggests that the percentage of fat above which can be defined as obesity is between 23% and 25% in men and between 30% and 35% in women.

The clinical use of the WHO BMI cut-off values, when applied for example to a population such as the Italian one, causes classification errors and a considerable number of subjects, both male and female, who are not classified as obese on the basis of the body mass index only.

The disagreement has become staggering in the classification of obese women: in the 30-40 age group the percentage of obese women according to the BMI is 30% reaching about 82% if the classification is based on the percentage of fat. 

This result dovetails exactly with our data collected in over 25 years of body composition analysis, and with another study carried out by Prof. Braverman, presented at the American Association of Clinical Endocrinologists meeting in Boston.

4. Conclusion

The real percentage of obesity is about 3 times greater than that estimated with the BMI, therefore about 80-90% of the world's population suffers from it.

Especially those with a low amount of muscle mass and an excess of fat mass, defined as "fake thin" can easily be classified as obese with a normal BMI.


  1. Review: World J Gastroenterol. 2016 Jan 14;22(2):681-703.doi: 10.3748/wjg.v22.i2.681.
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