Current medical methods for diagnosing obesity rely on body mass index, which is not a reliable measure of health or disease at the individual level. This may lead to misdiagnosis with negative consequences for people with obesity. On the other hand, scientists are seeking to provide a new approach.
In a report published in the journal Lancet Diabetes and Endocrinology, the “Clinical Obesity Panel” presented a new and accurate approach to diagnosing obesity, based on other measures of excess body fat in addition to the body mass index (BMI), and objective signs and symptoms of poor health at the individual level.
The committee was headed by Professor Francesco Rubino, from King’s College London, and its report was written about by the Eurick Alert website.
The panel featured 56 world-leading experts in a wide range of medical specialties, including endocrinology, internal medicine, surgery, biology, nutrition and public health, representing many countries and diverse healthcare systems. The panel also included people living with obesity and looked in particular at the potential impact of new definitions of obesity on widespread societal stigma.
The committee recommended a new, accurate approach where body fat measures – for example waist circumference or direct fat measurement – are used in addition to BMI to detect obesity, thus reducing the risk of misclassification.
New division
In addition, the authors introduce two new diagnostic categories for obesity based on objective, individual-level measures of disease; “Clinical obesity” (a chronic disease associated with persistent organ dysfunction due to obesity alone) and “preclinical obesity” (associated with a variable level of health risk, but without persistent disease).
The panel’s authors call on all people living with obesity to receive personalized health counseling and evidence-based care when needed – free of stigma and blame – with different strategies for clinical obesity and preclinical obesity.
The proposal is designed to address limitations in the traditional definition and diagnosis of obesity that hinder clinical practice and healthcare policy, resulting in individuals with obesity not receiving the care they need. By providing a medically coherent framework for diagnosing the disease, the committee also aims to settle the ongoing dispute over the idea of obesity as a disease, which has been at the heart of one of the most controversial and polarizing debates in modern medicine.
“The question of whether obesity is a disease is flawed because it assumes an implausible all-or-nothing scenario in which obesity is either a permanent disease or never a disease,” says committee chair Professor Francesco Rubino. “But the evidence points to a more nuanced reality. Some affected individuals “Those with obesity can maintain normal organ function and general health, even in the long term, while others experience signs and symptoms of severe disease here and now.”
He added: “Viewing obesity only as a risk factor, rather than a disease, can unfairly deny access to time-sensitive care among people who are in poor health due to obesity alone. On the other hand, a blanket definition of obesity as a disease can lead to “Overdiagnosis and unjustified use of medications and surgical procedures, with potential harm to the individual and significant costs to society.”
“Our reconceptualization recognizes the nuanced reality of obesity and allows for personalized care,” he said. “This includes timely access to evidence-based treatments for individuals with clinical obesity, as appropriate for people with chronic disease, as well as risk-reducing management strategies for those with chronic obesity.” “This would facilitate rational allocation of healthcare resources and fair and medically meaningful prioritization of available treatment options.”
Current methods for diagnosing obesity are ineffective
There is an ongoing debate among clinicians and policymakers about the current diagnostic approach to obesity, which tends to misclassify excess body fat and misdiagnose the disease.
Part of the problem is that obesity is currently defined by BMI, with a BMI greater than 30 kg/m2 considered an indicator of obesity.
Although BMI is useful for identifying individuals at increased risk of health problems, the committee highlights that BMI is not a direct measure of fat, does not reflect its distribution around the body, and does not reflect its distribution in the body. These data do not provide information about health and disease at the individual level.
Committee member Professor Robert Eckel, from the University of Colorado Anschutz in the United States of America, said: “Relying on the BMI alone to diagnose obesity is problematic, as some people tend to store excess fat at the waist or in and around their organs, such as the liver, heart, or muscles. This is associated with higher health risks compared to storing excess fat just below the skin in the arms, legs or other areas of the body, but people with excess body fat do not always have a BMI that indicates that they are living with obesity, which means that “Their health problems may go unnoticed. In addition, some people have a high body mass index and high body fat percentage but maintain normal organ and body functions, without any signs or symptoms of ongoing disease.”
Beyond BMI
While learning about BMI is useful as a screening tool to identify people who may be living with obesity, the authors recommend moving away from detecting obesity based on BMI alone. Instead, they recommend confirming excess fat mass (obesity) and its distribution around the body using one of the following methods:
- At least one body size measurement (waist circumference, waist-to-hip ratio or waist-to-height ratio) plus body mass index.
- At least two body size measurements (waist circumference, waist-to-hip ratio or waist-to-height ratio) regardless of BMI.
- Directly measuring body fat (such as a bone density scan or DEXA) regardless of BMI.
- In people with a very high BMI (eg >40 kg/m2) excess body fat can be feasibly assumed.
Two new categories of obesity
The committee also presents a new model for diagnosing diseases in obesity based on objective measures of the disease at the individual level.
First: clinical obesity
Clinical obesity is defined as a state of obesity accompanied by objective signs and/or symptoms of decreased organ function, or a significant reduction in the ability to perform standard daily activities, such as bathing, dressing, eating, and controlling urination, directly due to excess body fat. People with clinical obesity should be considered to have an ongoing chronic disease and should receive appropriate management and treatments.
The committee identified 18 diagnostic criteria for clinical obesity in adults including:
- Shortness of breath caused by the effects of obesity on the lungs.
- Heart failure caused by obesity.
- Knee or hip pain, with joint stiffness and decreased range of motion as a direct effect of excess body fat on the joints.
- Some changes in the bones and joints in children and adolescents that limit movement.
- Other signs and symptoms are caused by dysfunction of other organs including the kidneys, upper airways, metabolic organs, nervous, urinary, reproductive, and lymphatic systems in the lower extremities.
Second: Preclinical obesity
Preclinical obesity is a state of obesity with normal organ function. “People living with preclinical obesity therefore do not have persistent disease, although they are at variable but generally increased risk of developing clinical obesity and many other non-communicable diseases in the future, including type 2 diabetes and cardiovascular disease.” Certain types of cancer and mental illness, among others. As such, they should be supported to reduce the risk of developing potential diseases.”
“The new diagnostic criteria developed by the Commission fill the gap in the concept of diagnosing obesity because they enable doctors to distinguish between health and disease at the individual level,” said committee member Dr. Godin Galea, from the WHO Regional Office for Europe. “We hope that it will ensure widespread support for the new framework and diagnosis of obesity.” By many important scientific societies from around the world, systematic clinical assessment of obesity becomes a basic requirement in health systems worldwide.
People with clinical obesity should receive timely treatment, with the aim of completely restoring or improving body functions that have decreased due to excess body fat, rather than just losing weight. The type of treatment and management for clinical obesity – lifestyle, medications, surgery, etc. – should be determined based on individual risk-benefit assessments and determined through active discussion with the patient.
Health insurance companies around the world often require evidence of other obesity-related conditions (such as type 2 diabetes) to provide coverage for obesity treatments. As a distinct chronic disease in its own right, clinical obesity should not require the presence of another disease to justify coverage.