HQ Team
January 16, 2025: Obesity, as defined by the standard body mass index, is erroneous, and the condition should be split into two — pre-clinical and clinical, according to an international commission.
People with a medical condition caused by their weight have “clinical obesity,” and those who are fat but fit and at risk of disease must fall under “pre-clinically obese,” according to a new definition of obesity that was endorsed by 76 organisations around the world.
Currently, the body mass index (BMI), a standard procedure, relies on a healthy weight for people’s height to define obesity.
Public health strategies to reduce the incidence and prevalence of obesity must be based on current scientific evidence, rather than unproven assumptions that blame individual responsibility for the development of obesity, according to the report.
Bias, stigma
Weight-based bias and stigma were major obstacles in efforts to effectively prevent and treat obesity. Healthcare professionals and policymakers should receive proper training to address this important issue of obesity.
The report, published in The Lancet Diabetes & Endocrinology journal, is supported by 58 medical experts around the world.
The experts focus more on how much body fat and the medical complications the person has rather than just their weight.
“Current BMI-based measures of obesity can both underestimate and overestimate adiposity and provide inadequate information about health at the individual level, which undermines medically sound approaches to health care and policy.
‘Excess adiposity’
“This Commission sought to define clinical obesity as a condition of illness that, akin to the notion of chronic disease in other medical specialities, directly results from the effect of excess adiposity on the function of organs and tissues,” the experts wrote in the journal.
They defined clinical obesity as a “chronic, systemic illness” characterised by alterations in the function of tissues, organs, the entire individual, or a combination thereof, due to excess adiposity.
Clinical obesity can lead to severe end-organ damage, causing life-altering and potentially life-threatening complications such as heart attack, stroke, and renal failure.
People with any of the 18 medical conditions caused by obesity — 13 for children and adolescents — require medical treatment to improve their health and prevent serious injuries to organs.
Cardiovascular disease
Preclinical obesity was defined “as a state of excess adiposity with preserved function of other tissues and organs and a varying, but generally increased, risk of developing clinical obesity” and other non-communicable diseases such as type 2 diabetes, cardiovascular disease, certain types of cancer, and mental disorders.
This meant that people who had a BMI over 25 and too much fat but who were otherwise healthy should pretty much be left alone. They should be monitored and counselled not to gain any more weight and possibly to lose some.
“We recommend that BMI should be used only as a surrogate measure of health risk at a population level, for epidemiological studies, or screening purposes, rather than as an individual measure of health.”
Excess adiposity should be confirmed by either direct measurement of body fat, where available, or at least one anthropometric criterion such as waist circumference, waist-to-hip ratio, or waist-to-height ratio in addition to BMI, using validated methods and cutoff points appropriate to age, gender, and ethnicity, according to the experts.
‘BMI can be misleading’
Adiposity refers to body fat. Adipocytes and adipose tissue store the greatest amount of body lipids, including triglycerides and free cholesterol.
If the recommendations are accepted, they could change doctors’ perceptions of who needs to be treated for obesity and it would also affect the use of prescription drugs that treat obesity.
Prof Tom Sanders, Professor Emeritus of Nutrition and Dietetics at King’s College London, said the report contained an important set of recommendations that define the clinical syndrome of obesity and differentiate it from an excess accumulation of body fat in the presence of normal bodily function.
“The report is based on a Delphi review where consistency of agreement on views for the treatment of obesity is sought from experts. In most cases the agreement was 100 percent and in a few cases 95 percent.
“Body mass index is currently used to define obesity and while it is useful for looking at groups of people it can be misleading in the range of BMI 25-34.9.
“For example, there are a few individuals who are muscle-bound and have low levels of body fat but have a BMI in the range of 30-35,” he said.
