Doctors have proposed new diagnostic criteria for assessing obesity in Indians, taking into account body size, body fat and possible organ dysfunction, asserting that the body mass index (BMI) alone is an unreliable measure for health and illness.
The revised criteria proposed by a nationwide panel of doctors define values of BMI — the weight in kilograms divided by the height in metres squared — greater than 23 without any effects on routine daily activities or organ functions as “obesity without
consequences”.
But BMI values greater than 23 coexisting with excess abdominal fat, waist circumference, waist-to-height ratio, diabetes or conditions like knee arthritis precipitated by excess weight are to be considered “obesity with consequences”, requiring intensive management and risk mitigation.
“The criteria are designed to facilitate early diagnosis and management to lower the health risks that come with obesity,” Anoop Misra, chairman of the Fortis CDOC Hospital for Diabetes and Allied Sciences, New Delhi, who led the revision exercise, told The Telegraph.
Amid mounting evidence that Indians have a unique tendency to accumulate fat around the abdomen, Misra and his colleagues had in 2009 published a consensus statement defining BMI 18-22.9 as normal weight, BMI 23-24.9 as overweight, and BMI greater than 25 as obese.
However, new research has highlighted what medical experts have described as shortcomings of using BMI alone to diagnose obesity. Multiple studies over the past 15 years have also suggested that abdominal fat contributes to inflammation and the early onset of chronic health disorders.
The revision for Indians introduces two distinct stages of obesity at BMI values greater than 23. People in stage I or “obesity without consequences” need to be careful that they do not slip to stage II or “obesity with consequences”. People in stage II obesity would require tailored weight reduction strategies.
These classifications offer a clear, rational approach to tackling obesity, said Naval Vikram, professor of internal medicine at the All India Institute of Medical Sciences, New Delhi, who collaborated with Misra and other medical experts in defining therevised criteria.
The proposal by the Indian doctors is in line with new recommendations by an international medical panel for a nuanced strategy that requires measurements of waist circumference, waist-to-hip ratio, waist-to-height ratio and body fat measurements with BMI to assess obesity.
The 56-member International Commission for Clinical Obesity has recommended diagnostic criteria for two categories of obesity — clinical obesity, marked by ongoing organ dysfunction, and pre-clinical obesity, marked by high risk but no ongoing illness or organ dysfunction.
The commission’s recommendations were published on Tuesday in The Lancet Diabetes and Endocrinology, a research journal.
“BMI is an imperfect measure that does not distinguish between body fat, muscle mass and bone density,” said Misra, who is also a member of the international commission. “Traditional BMI cutoffs often misclassify South Asian populations who typically show dangerously high abdominal fat at even low BMI values. Splitting obesity into two stages helps rationalise the intensity of treatment.”
Both the revisions for India and the commission’s recommendations are rooted in growing evidence that some individuals with obesity may maintain normal organ functions and overall health even in the long term while others display signs of potentially severe illness even at lowBMI values.
“Considering obesity as a risk factor and disease can unfairly deny access to time-sensitive treatment for people who are experiencing ill health due to obesity itself,” said Francesco Rubino, chair of metabolic and bariatric surgery at King’s College, London, the commission’s chair.
“On the other hand, a blanket definition of obesity as a disease could result in overdiagnosis and unwarranted use of medications or surgical procedures, with potential harm to the individual and costs to society,” Rubino said in a media release.
