in the middle The buzz around Ozempic and similar weight loss drugsA team of 58 researchers is questioning the way obesity it is defined and diagnosed, arguing that the current methods do not capture the complexity of the situation. They offer a more nuanced view.
of the group revised definitionpublished in The Lancet Diabetes and Endocrinology on January 14, examines how excess body fat, a measure called adiposity, affects the body. based only on body mass index (BMI).which relates a person’s weight to their height. They propose two categories: preclinical obesity, when a person has excess body fat but their organs function normally, and clinical obesity, when excess fat damages the body’s organs and tissues.
This change may improve clinical care, public health policies and society’s attitudes towards obesity, says Elisabeth van Rossum, an endocrinologist at the Erasmus University Rotterdam center in the Netherlands.
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“Now the idea is, eat less, move more and you’ll lose weight,” says Van Rossum, who was not involved in the work. Although a healthy lifestyle is important, he added, “if it were that simple, we wouldn’t have an epidemic, and this document is an excellent contribution to the debate on the complexity of obesity”.
Global problem
More than 1 billion people worldwide live with obesity, and approximately 5 million people die each year from such disorders. diabetes and cardiovascular diseases.
Because it is easy to measure and compare, BMI has long been used as a tool to diagnose obesity. But it doesn’t provide a complete picture of a person’s health because it doesn’t take into account differences in body composition, such as muscle and fat.
For people of European descent, obesity is usually defined by a BMI of 30 or more, which correlates with high levels of body fat. However, a muscular athlete could be labeled obese based on their BMI, while someone with a “normal” BMI could be overweight, which increases their risk of heart problems or other serious health problems, says bariatric surgeon Francesco Rubino of King’s College. London, who led the group proposing the new approach.
Conventional methods lead to unnecessary treatment for some people and miss others who need help, he says. To address this, Rubino and his colleagues propose a system for diagnosing obesity that goes beyond BMI, combining it with other methods, such as measuring waist circumference, which is a proxy for adiposity, or body scans using low-level X-rays, which. measure fat mass directly.
Although there is no fixed threshold for obesity, body fat is usually considered excessive when it is above 25% in men and 30-38% in women. Because directly measuring adiposity may be impossible or expensive, alternative health markers such as waist size, waist-to-hip ratio or waist-to-height ratio are important, the researchers say. However, they added, it is safe to say that a person with a BMI over 40 has a lot of body fat.
Diagnosing obesity should also take into account the results of standard laboratory tests, medical history and information about daily activities to assess how excess fat can affect a person’s health, says study author Robert Eckel, an endocrinologist at the University of Colorado Anschutz Medical Campus. in Aurora “These are objective diagnostic criteria that are standardized across global health systems,” he says.
Personalized assessments that take age, gender and ethnicity into account are equally important, as certain groups may have health risks at lower BMI thresholds than others, says Louise Baur, a pediatrician at the University of Sydney in Australia.
Two categories
Even though people with preclinical obesity have normally functioning tissues, they are at a higher risk of developing health problems than people who are not obese. Counseling and preventative measures, such as lifestyle changes, can help reduce the risk of more serious health problems, the team says.
Clinical obesity occurs when excess fat damages organs or severely limits daily activities, such as walking or getting dressed. People with clinical obesity may need treatments aimed at improving health and preventing complications.
Rubino notes that this approach is especially important with the growing use of weight-loss drugs because it helps provide more accurate diagnoses and makes treatment effective and cost-effective.
Challenging stigma
The approach, which has contributed to dozens of scientific groups and patient advocacy around the world, reflects the growing evidence of the health consequences of obesity, Van Rossum says. Another framework published last year also agreed that the diagnosis of obesity should go beyond BMI to include an assessment of its effects on health.
Yet many health care providers still see obesity as a problem of willpower rather than a disease caused by excess fat, regardless of its underlying causes — which can include hormonal changes and genetic factors, Van Rossum says. In the Netherlands, for example, a study he authored found that most people with obesity experienced stigma in the health care field. This stigma often prevents people from seeking care, highlighting the need for better education and communication about the condition.
Although the latter approach aims to provide a more accurate picture of obesity, it is not clear whether it will lead to more or less diagnosis, or how it will affect the management of the condition in the clinic. “Over time, we hope to incorporate this type of assessment into clinical practice guidelines,” says Baur.
This article is and was reproduced with permission first published January 14, 2025.
