Who exactly is an obese person? New research redefines guidelines and fat and BMI facts everyone should know |
Obesity has long been measured using the BMI, Body mass index, a simple ratio weight to height. While this has been used widely for a long time, it does not account for fat distribution, muscle mass or the actual impact of excess adiposity on the body’s organs. A landmark study published in JAMA Network Open, on October 15, challenges this traditional approach, proposing a more comprehensive definition that could dramatically change how obesity is being diagnosed and treated. A recent consensus guideline published in The Lancet Diabetes & Endocrinology proposed a new definition of obesity that incorporates anthropometrics and/or direct measures of body fat to better differentiate adipose tissue excess.
A new framework for defining obesity

This study, led by Dr. Lindsay T. Fourman, and colleagues, introduces a nuanced classification of obesity that goes beyond BMI. According to the JAMA Network Open article:BMI-plus anthropometric obesity: Individuals with BMI above the traditional threshold plus at least one elevated anthropometric measure or BMI greater than 40Anthropometric only obesity: Individuals with at least two elevated anthropometric measures but BMI below the traditional thresholdObesity was further categorised as clinical or pre-clinical, based on the presence of organ dysfunction and or physical limitation. This approach further enables clinicians to distinguish between individuals at immediate risk for obesity-related health issues and those in earlier potentially preventable stages.
What is anthropometric obesity:
It refers to the type of obesity identified using measurement of the body fat distribution and body size, rather than just overall weight or BMI. In simple words, it is defined by physical measurements of the body, that indicate excess fat in specific areas, which are strongly linked to health risks.Dramatic increase in obesity prevalenceApplying this refined framework, it revealed striking results. Among the participants aged 70 years or older, nearly 80% qualified as obese, a substantial increase compared to how traditional measurements would classify them. It has also attested the fact that nearly 70% of the adults in the United States of American are under the new obesity guidelines, a sharp jump from the roughly 43% under the old BMI measures, and this is a shocking jump compared to all other traditional methods.This study also identified individuals who may have a slightly elevated BMI but show elevated anthropometric measures such as waist circumference, or organ impairment. These individuals, previously overlooked, are now being recognised at a significant risk of diabetes, cardiovascular diseases and other health complications.
Clinical implications
The new framework has shared important implications for its treatment and public health:Targeted pharmacotherapy: Anti-obesity medications are often prescribed based on BMI thresholds, under this new criteria, individuals with clinical obesity, even at lower BMI levels, could become eligible for medication, while those without organ dysfunction may not require pharmacological intervention.Lifestyle interventions: Personalised diet plans, exercise and behavioral programs for individuals identified with preclinical obesity can prevent progression to organ dysfunction and severe complications.Policy and healthcare planning: Screening programs, treatment guidelines and resource allocation, may need to evolve to accommodate the increased number of individuals now classified as obese under this new framework.
Beyond BMI: A paradigm shift

This study aligns with the global movement to recognise obesity as a chronic relapsing disease, that requires long-term management. By incorporating, anthropometric measurements and organ health into the definition of obesity,healthcare providers can:Detect at-risk individuals earlierPersonalise treatment and prevention strategiesImproves outcomes by addressing both physical and metabolic complications.
What should we do
Practical advices remain at the center, but with a sharper purpose:Go beyond the BMI: Ask the doctor, whether should one measure waist circumference, waist to hip ratio or go for body fat scans.Healthier habits: A lifestyle which includes, exercise, proper diet and strength training should be adopted

Keep a check on metabolic markers: Lipid profiles, blood sugar levels, and cholesterol are all early markers that can help with detection.The JAMA Network Open study provides compelling evidence for adopting a more comprehensive definition of obesity. By classifying obesity as BMI-plus- anthropometric or anthropometric only and distinguishing clinical vs pre-clinical, this framework allows for a more accurate identification of individuals at risk. As the obesity rate continues to rise in the world, it has become necessary to know what actually is obesity, not just on the weighing machine, but in reality and in numbers, moving beyond BMI for a true measure of health impact.
