Doctors are proposing a "radical overhaul" of how obesity is diagnosed globally amid fears that reliance on body mass index could lead to millions of people being misdiagnosed.

More than 1 billion people are thought to have the condition, which for decades has been diagnosed by measuring a person's BMI (height to weight ratio) to estimate the amount of excess body fat.

However, there are concerns that body mass index itself is not a "reliable measure" of an individual's health and could lead to under- and over-diagnosis of obesity, with "negative consequences" for those affected and wider society.

Dozens of the world's leading experts from a wide range of medical specialties, including endocrinology, internal medicine, surgery, biology, nutrition and public health, are now calling for a "redefinition" of a disease that causes significant harm and costs on every continent. Nation billions.

Relying on body mass index alone is "ineffective" because it is not a direct measure of fat, does not reflect the distribution of fat around the body, and does not provide insight into a person's health, according to a report published by The Lancet Diabetes and Diabetes Experts. information. Journal of Endocrinology.

The proposed restructuring, endorsed by more than 75 medical organizations worldwide, proposes new ways to diagnose obesity based on other indicators of excess body fat besides BMI, such as waist-to-hip ratio or waist-circumference ratio. height proportions, and objective signs and symptoms of poor health.

Currently, some people with excess body fat have a body mass index that does not indicate obesity, meaning potentially serious health problems go unnoticed and untreated. Meanwhile, other people with a higher body mass index may be diagnosed as obese despite maintaining normal organ and body function and showing no signs or symptoms of ongoing disease.

Professor Francesco Rubino, chair of the Lancet committee that wrote the report, said the changes would provide an opportunity for global health systems to adopt a common, clinically relevant definition of obesity and more accurate diagnostic methods.

He said: "The question of whether obesity is a disease is flawed because it assumes an implausible all-or-nothing scenario, whereby obesity is either always a disease or it never is a disease However, evidence points to a more nuanced reality. Some obese people maintain normal organ function and overall health over the long term, while others exhibit signs and symptoms of severe disease in the here and now.

“Considering obesity solely as a risk factor, rather than as a disease, may unfairly deprive people who suffer from poor health outcomes solely from obesity the opportunity to receive timely care. On the other hand, defining obesity broadly as A disease can lead to overdiagnosis and inappropriate use of medications and surgeries, causing potential harm to individuals and significant costs to society."

Experts recommend two new categories of obesity: clinical obesity and preclinical obesity.

Clinical obesity is defined as obesity that is associated with objective signs and/or symptoms of reduced organ function or that is directly due to excess body fat and results in a significant reduction in the ability to perform standard daily activities such as bathing, dressing, or eating. Experts say patients with clinical obesity should be considered to have an ongoing chronic condition and receive appropriate management and treatment, such as weight loss medications.

Preclinical obesity is defined as obesity with normal organ function. Therefore, people with preclinical obesity do not suffer from persistent disease, although they are at future risk for clinical obesity and other diseases, including type 2 diabetes, cardiovascular disease, certain types of cancer, and psychiatric disorders. Differences, but generally increased. Experts say support should be provided to this group of people to reduce the risk of underlying diseases.

"Our redefinition acknowledges the nuanced reality of obesity and allows for personalized care," said Rubino, director of metabolic and bariatric surgery at King's College London.

The Royal College of Physicians welcomed the report. Dr Kath McCullough, special adviser on obesity, said: "For too long we have relied on BMI as a simple measure of obesity, which often distorts the facts and fails to fully reflect how excess body fat affects a person's health.

"The committee's distinction between preclinical and clinical obesity represents an important step forward, emphasizing the need for early identification and intervention while providing appropriate care for those who are already suffering serious health consequences."

However, Catherine Jenner, director of the Obesity Health Alliance, said the priority should be supporting those who are overweight "rather than just focusing on how weight is measured".