BMI isn’t an accurate tool to diagnose obesity: Study

BMI isn’t an accurate tool to diagnose obesity: Study

DurgeshNandan.Jha@timesofindia.com 15.01.2025

New Delhi : Do you think you are not obese according to your Body Mass Index? You may be mistaken, as a global commission convened by The Lancet Diabetes & Endocrinology, a reputed medical journal, has now argued that BMI provides inaccurate results in assessing obesity. Doctors should confirm whether a person is obese using at least one other body measurement — such as waist circumference or by directly measuring body fat, it has suggested. 

BMI is a medical screening tool that measures ratio of a person’s height to her or his weight to estimate amount of body fat she or he has. Current definition says a person with a BMI of 30 kg/m2 and above can be considered obese. According to Lancet Commission’s report, released Tuesday, people with excess body fat do not always have a BMI above 30, meaning that their health risk can go unnoticed. Similarly, it says, individuals with high muscle mass (for example, athletes) tend to have high BMIs despite normal fat mass and diagnosing them as having obesity or adisease was inappropriate.

 “Relying on 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, and this is associated with a higher health risk compared to when excess fat is stored just beneath the skin in the arms, legs or in other body areas. But people with excess body fat do not always have a BMI that in dicates they are living with obesity, meaning their health problems can go unnoticed. Additionally, some people have a high BMI and high body fat but maintain normal organ and body functions, with no signs or symptoms of ongoing illness.” 

Robert Eckel, a professor at the University of Colorado Anschutz Medical Campus, who was part of the expert group, said. Dr Anoop Misra, a doctor from India who was in the expert committee, added: “Abdominal obesity is common in India. Existing criteria based on BMI measurement often fails to classify them as obesity. The new classification will help remove this hurdle.” The Lancet Commission says not all persons having obesity need medical or surgical intervention. It has, for the first time, recommended subdividing obesity into two groups: clinical obesity and pre-clinical obesity, based on the presence or absence, respectively, of objective clinical manifestations (i.e., signs and symptoms) of altered organ function or impairment of an individual’s ability to conduct daily activities. Preclinical obesity often needs only monitoring and counseling, while clinical obesity may require treatment to prevent severe complications like heart attack, the Commission suggests.