BMI on Trial—Should It Still Define Obesity-BMI on Trial

Video Transcription

Video Summary

The session debated whether BMI should remain central to obesity diagnosis. Lee Perreault argued that BMI remains a useful, practical screening tool: it underpins much of the evidence on obesity prevalence and health risks, and thresholds for body fat and waist circumference are themselves largely derived from BMI. Although BMI can miss excess adiposity in some groups, she said waist measurements can help address those cases. She cautioned that requiring additional tests and signs of organ dysfunction could make diagnosis harder and leave many people untreated.<br /><br />Francesco Rubino clarified that the Lancet Commission does not reject BMI, but argues it cannot diagnose a disease on its own. The Commission distinguishes “preclinical obesity,” in which excess adiposity raises health risks, from “clinical obesity,” in which it impairs organ function or daily activities. Rubino said this distinction supports more individualized and proportionate care, and could improve treatment and insurance decisions rather than discouraging prevention.<br /><br />In rebuttal, Perreault warned that the Commission’s criteria could sharply reduce the number of people eligible for treatment and impose unrealistic assessment requirements. Rubino responded that accurate diagnosis is essential and that risk states can also warrant treatment; labeling everyone with obesity as having the same disease may hinder tailored care.<br /><br />Audience questions addressed inconsistent prevalence estimates, patient motivation, stigma, and how newer measurements relate to BMI. The speakers agreed that communication and patient circumstances matter, but differed on whether a preclinical label or a broader disease diagnosis would best support patients.

Keywords

BMI

obesity diagnosis

waist circumference

body fat

Lancet Commission

preclinical obesity

clinical obesity

organ dysfunction

obesity prevalence

health risks