A committee of experts proposes rethinking the concept of obesity: “We need a radical change”
The commission asks not to always classify it as a disease, to banish the BMI as the only criterion and to differentiate between clinical and preclinical obesity
Obesity is a disease of the future that is being analysed using methods from the past . According to the United Nations, by 2030 there will be more than 1.2 billion obese adults in the world , 200 million more than today. They will be diagnosed as such using the body mass index (BMI), a mathematical formula created in the 19th century that has become outdated. The very concept of obesity as a disease, as a dichotomous, black-and-white issue, has many detractors. Clinical obesity is displayed on a grey scale. These are the main conclusions of a global commission, supported by more than 75 medical organisations from around the world, which is published this Tuesday in the scientific journal The Lancet Diabetes & Endocrinology .
“ We need a radical change. We have found ourselves in a dead end with obesity,” explains Professor Francesco Rubino , Professor of Endocrinology at King’s College London and Chairman of the Commission , in a telephone conversation . “ Our definition of obesity does not tell us who is sick and who is not. It does not differentiate between who may need future care and who needs medical help in the present, urgently, ” he laments. This has clinical, health and political consequences . For this reason, the document proposes creating two new subcategories, differentiating between clinically obese people, those whose obesity is impacting on their health and who should be classified as sick; and preclinically obese people, people whose obesity is not impacting on their health . In this case, they explain, it should not be understood as a disease, but as a risk factor.
The idea is not shared by the entire scientific community . “ It is the same disease, but it gets worse if we let it progress, just like what happens with prediabetes and diabetes ,” says Cristóbal Morales , an endocrinologist at the Virgen Macarena University Hospital in Seville. “ That is why I believe that we must act early.” Morales is a member of the Spanish Society for the Study of Obesity and did not participate in the study. He values many of its postulates in a positive way, which he defines as “revolutionary” because they are easily applicable in consultation . But he does not fully agree with the definition of preclinical obesity as a simple risk factor . The European Association for the Study of Obesity published last July in Nature a new framework for diagnosis in which it considers that every person with obesity is sick . From that perspective, the new study published by Lancet “ misses a magnificent opportunity for a holistic and early approach to prevent complications ,” says Morales.
Rubino understands, but refutes these criticisms. “ They come from people who have been fighting for years to have obesity recognized as a disease. We have lived in trenches and this spirit of defense leads us to distort the reality of obesity ,” he says. At the same time, the expert recalls that preclinical obesity is described in the study as a problem. “ But not all problems or risk factors can be diagnosed as a disease. Living in the city is not a disease, but breathing a polluted environment is not exactly healthy either ,” he summarises.
“BMI is a social justice issue”
The article criticises the validity of the BMI, the obesity equation . In modern medicine, with sophisticated devices that measure body composition, and the way excess weight can affect our health, a simple number decides who is obese and who is not. This is obtained by dividing a person’s weight by their height squared. If the result is greater than 25, the patient is overweight. If it is over 30, they are classified as obese. “There are many people who believe they can self-diagnose by entering those two pieces of data into Google, but clinical diagnosis does not work like that ,” says Rubino.
Jose Manuel Fernandez-Real , an endocrinologist and professor at the University of Girona who participated in the commission, is also critical, but acknowledges that this easy and intuitive measure “ may have its value ” in calculating the obesity of a population in an epidemiological way. But it would be a sociological tool, not a clinical one. AndFernandez-Realpoints out that even in this case it introduces confounding factors. “The result depends on ethnicity, age, sex… it is very variable and gives very biased information.” The BMI was created with a Caucasian patient in mind. But today many countries have a multiethnic reality and health policies are being taken with this data. “This situation lays the foundations for discrimination,” explains Rubino. “It is not only a medical problem, but one of social justice.”
Furthermore, the BMI does not take into account the composition of that weight, which can come from excess fat or muscle. The best example of its limitations is offered by the National Football League (NFL), where 97% of players have a BMI greater than 25 (which could be classified as overweight) and more than half, 56%, would be obese according to this index, having a BMI greater than 30. A scientific study from 2018 pointed out the overestimation of the obesity rate in this sport, when in reality, upon closer analysis, it can be seen that the majority are athletes with a relatively low fat percentage.
BMI is the scale that decides who is in and who is out of access to weight-loss surgery or drug treatment. In the case of GLP1 agonists, for example, Ozempic is prescribed to those with type 2 diabetes , an objectively diagnosable disease. But Wegovy, indicated for those with obesity, is prescribed to patients with a BMI above 30 or above 28 with significant comorbidities. Thus, in theory, more than half of NFL players could get this drug, but a person with much more fat, but with a BMI of 27, would be left out.
The commission’s text proposes ending these injustices by combining BMI with body fat measurements (for example, waist circumference or direct fat measurement) and up to 18 criteria to analyse signs of disease and make a differential diagnosis. “ This has always been a problem ,” explains Rubino, “ but today it cannot be justified because there is an alternative. Because we can diagnose who is obese and who is not much more precisely, without wasting resources on those who do not need them and without leaving out people who need them.”
Olga González Albarrán , head of the Endocrinology and Nutrition Service at the Gregorio Marañón Hospital , agrees with the idea of going beyond the BMI.The doctor, who was not involved in the study, points out that it could have political consequences. “Right now obesity is being overestimated globally because it is measured in this way,”she explains. “And there are many patients who, despite having a high BMI, do not have signs and symptoms derived from excess fat or alterations in their activities.” The endocrinologist also highlights that the analysis takes into account “the stigmatization and guilt that are associated with this disease.” This does not happen with other diseases linked to lifestyle, she points out, and it introduces biases and prejudices in the way we understand obesity.
Obesity is the fifth risk factor for death in the world . Every year 2.8 million adults die as a result of this condition. It kills and limits like a disease, but its origin is multifactorial. Obesity may be a disease, but it is also many other things. Its classification as such is one of the most complex open debates in modern medicine. This paper reflects the general feeling based on scientific evidence. But it is far from being the last word on a complex condition in which medical, social and even emotional factors are mixed.
Author: Enrique Alpañes
Date: Madrid – 15 JAN 2025 – 05:20 CET
Source: The Country
Note: The Nutrigenomics Institute is not responsible for the opinions expressed in this article.
PHOTO BY PIXABAY.
