A day after international experts proposed a new approach to define obesity by looking beyond body mass index (BMI), Indian doctors have drawn up similar guidelines. India-specific guidelines are crucial because Indians typically possess higher body fat percentages compared to other ethnic groups and tend to develop diabetes at lower BMI than others. Therefore, the previous Western BMI cutoffs for overweight (25kg/m2) and obesity (30kg/m2) were considered lenient for Indians, who often present with a thin-fat physique—a term to describe people who appear lean but have a higher percentage of body fat than expected.
The new Indian guidelines, drawn up by endocrinologists from the Diabetes Foundation India after a gap of 15 years and published in ‘Diabetes & Metabolic Syndrome: Clinical Research & Reviews’ on Wednesday, set a BMI of 23kg/m2 as the dividing line for pre-clinical (stage 1) and clinical (stage 2) obesity levels among Indians.
“Body fat is the gold standard for defining obesity… whenever possible, it should be estimated,” say the guidelines. For clinicians and epidemiologists, the paper said BMI should be used to define generalised obesity, that is, any person having a BMI of more than 23kg/m2. Delhi-based endocrinologist Dr Anoop Misra, one of its authors, said, “Our cutoff… as well as the lower waist-to-hip ratio is based on ethnic specifications.”
Though global guidelines have downgraded the use of BMI, he said in the Indian context it is not always easy to get the right body fat reading: there are very few studies in India or globally to set body fat standards. “One will always find a variable range for body fat, with most stating that 25% of body fat is okay for men and 38% for women,” he said. Secondly, in India, it’s not easy to get a good estimation of body fat: most clinics and hospitals have a basic apparatus that has low accuracy. “The good machines cost a lot and few clinics and hospitals invest in it,” said Dr Misra.
City endocrinologist Dr Shashank Joshi said the obesity paradigm is changing. “As per the new thought process, adiposity (the amount of body fat a person has) is what really matters. The excess fat around organs such as the liver, heart and ovaries is the key,” he said. The need to move beyond BMI was felt to prevent both under- and over-diagnosis of obesity-related health risks, especially with the availability of weight-loss injections and pills.
“As per the new definition, obesity is a three-tier disease affecting metabolic, mechanical and mental health,” said Dr Joshi. For the first time, obesity has been defined in clusters. “We now have clear-cut ways to treat it when it’s mild (with lifestyle interventions, diet, behaviour) and medicines and with endoscopic or surgical interventions when it’s morbid.”
