Arnold Schwarzenegger and Teddy Riner have an unexpected common point: they are both considered obese. There is no doubt that the 142 kilos of French judoka are more made up of muscles than fat. But the body mass index (BMI), the global reference for decades to measure obesity, does not make this distinction. An aberration that 58 international experts propose to correct by giving a new definition of obesity.
In a report published in mid-January by the prestigious medical journal The Lancetthese scientists believe that BMI is an insufficient criterion today. Instead, they recommend a more precise diagnosis, taking into account in particular the waist tour and distinguishing two forms of obesity, according to their health effects. On the one hand, preclinical obesity, which does not yet alter the patient’s health and is not considered a disease. On the other, clinical obesity, a “state of disease which results directly from the effect of excess adiposity on the function of organs and tissues”.
If this new classification was widely adopted, the implications would be massive. On the gaze of society, but also doctors on excess weight. On their way of deciding which patients should be treated. And on pharmacy industrialists who market anti -Besity drugs like Wegovy or Mounjaro. The distinction between clinical and preclinical obesity would make it possible to adapt the medical response to each patient: urgent care when excess body mass already affects health, monitoring and prevention when the organs still operate normally. Even before its publication, the report was approved by 76 health organizations around the world.
A step back?
In France, the initiative is variously perceived. “A group of doctors who work on the stigma of obesity had a rather favorable reception,” says Martine Laville, a nutrition professor at the Carmen laboratory of the Lyon I University and co -author of the report. His hope: that this report “helps to better recognize clinical obesity as a chronic disease, and therefore to better repay patients”. But among these, this opinion is far from being unanimous. Thus, Anne-Sophie Joly, president of the CNAO (national collective of obese associations), does not takeoff. She who has been fighting for years to have obesity recognized as an illness considers that this work goes in the wrong direction: “We come back to square one in terms of communication, it puts me out of me. Speaking of obesity Pluris, we send the message that, for some of the people concerned, it is not a pathology.
Currently, only the BMI allows you to say who is obese, and who is not. It is obtained by dividing the weight by the size to the square. A ratio invented in 1832 by the Belgian statistician Adolphe Qutelet, in search of the characteristics of the average man. Its first concrete application dates from the 1950s, when an American insurance company seized it. In 1997, the World Health Organization declared obesity global epidemic and then defined a threshold, based on the BMI. It is still in force today: if your BMI exceeds 30 kg/m², you are obese. For a person measuring 1.75 meters, this corresponds to a weight of 92 kilos.
With this criterion, about 17 % of French people are obese. The reality is more complex, since the BMI does not make the difference between fat and muscle. “This is a wonderful screening tool, but a bad individual diagnostic instrument,” recalls Dr. Guillaume Pourcher, obesity surgeon at the Geoffroy-Saint-Hilaire private hospital. In addition, this measure says nothing about the distribution of fats, however decisive for health. However, it is the accumulation of fat at the abdominal level which is a significant risk factor for many diseases.
Experts from Lancet took two years to achieve another approach to obesity. “At the start, I wondered if we really needed to embark on a new definition. I was not the only one, but these two years of work convinced me,” said Martine Laville. Within the expert community, the debates were lively. “On the need to go beyond BMI, consensus was easy to find,” says Martine Laville. The real challenges were elsewhere. First, agree on both precise and practical criteria. “How can we highlight this excess fatty mass? Medical imagery would be the perfect tool, but we needed simple measures, accessible all over the world,” recalls the co-author.
Repercussions on organs
The report proposal includes measures already practiced by many professionals: a size tour greater than 102 centimeters for men and 88 centimeters for women, a ratio of hnear-cutout greater than 0.9 for men and 0, 85 For women, as well as a height-cutter ratio more than 0.5. The rule is then simple. If the BMI is greater than 30 and one or two of these measures are exceeded, the person is considered obese. In addition, “a BMI greater than 40 is enough to presume obesity status”, notes the report.
“Then, it was necessary to answer the following question: does this excess fat fat have a impact on the organs?” details Martine Laville. In other words, is obesity-or not-a disease? A thorny subject, which has long divided experts. “To define obesity as an illness, scientific arguments needed to consider that this attack was caused directly by excess fat,” continues Martine Laville. At the launch of the work, the 58 experts had to respond to a survey: for more than half of them, obesity does not always fall under pathology. “They supported the idea that it is a risk factor for other diseases and, sometimes, a disease in itself,” recalls the report. With a main argument: “a significant number of people with excessive adiposity have no obvious sign of current illness.”
It is to agree that the authors ended up creating these two categories, preclinical obesity and clinical obesity. The latter indicates that excess fatty mass affects the patient’s health. To identify it, practitioners have developed 18 diagnostic criteria. In summary, we must ask ourselves whether overweight causes concrete difficulties in terms of health (significant shortness of breath, joint pain, sleep disorders, heart problems or poor sugar management) or in daily life (difficulty moving, washing , dress or eat).
Risk of confusion
Thus, a woman whose BMI exceeds 30 and whose waist tower exceeds 88 centimeters but has none of these signs must be considered in a state of preclinical obesity. His health is not yet degraded by his overweight. Which does not mean that it should not be followed by a professional. However, such a distinction makes it possible to better sign the care paths and follow -up. On the one hand, clinical obesity requires immediate treatment to slow down organs. On the other, preclinical obesity calls for personalized surveillance and advice. But this nuance between obesity-maladie and obesity without health alteration is controversial. Anne-Sophie Joly, president of CNAO and Doctor Guillaume Poucher fear for example that this report creates confusion, especially in our country, where the status of obesity remains vague.
The website of the Ministry of Health describes him as “illness”, but does not grant him the official status of chronic pathology. Recognition however recommended by Martine Laville in a report submitted in April 2023 to the Ministry of Health and which was to serve as a workplace. The promised roadmap to improve the care of the persons concerned has since lost in the meanders of government instability. With this definition of Lancetthere is a risk of breaking this dynamic, believes Anne-Sophie Joly: “By being blurred, we blur the message of public health, we will not improve the training of practitioners and the food industry will hear what she wants to hear. “
As a surgeon, Dr. Guillaume Pourcher fears “that these thinner diagnostic tools are used to limit access to therapeutic acts”. But he also sees it as an opportunity: “This approach could help us to better understand and explain obesity, both to professionals and to the general public. Today, we make the amalgamation between the causes and the aggravating factors and we Poorly detects. This is the hope of the authors of Lancet. It remains to be seen if, in France, this logic will eventually translate into the facts.
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