BMI below 25 but 43% Indians metabolically obese, finds ICMR study

CHENNAI: Nearly half of the population in India has a body mass index (BMI) less than 25, which puts them in the healthy weight range for adults. However, a study has shown that they are metabolically obese and should thus be categorised as metabolically obese non-obese (MONO).

According to the research conducted by the Indian Council of Medical Research-India Diabetes (ICMR-INDIAB), 43.3 percent of the population is metabolically obese.

Metabolism is the process by which the body converts food into energy, while BMI is a measure of weight relative to height. An individual with a BMI above 25 is considered overweight, while above 30 is considered obese.

While obesity usually produces cardio-metabolic dysfunction, some obese individuals are metabolically healthy, and conversely, some non-obese individuals have significant metabolic dysfunction. This study was conducted to assess the national prevalence of various obesity subtypes and their association with type 2 diabetes (T2D), coronary artery disease (CAD), and chronic kidney disease (CKD).

The study has found that MONO is more prevalent in men and in rural areas (46 per cent) than in urban India (39.6 per cent). Also, it showed the highest risk of chronic kidney diseases (CKD), especially among females.

The study was a cross-sectional survey of 1,13,043 individuals aged above 20 years from urban and rural areas across 31 states and union territories. In every fifth individual, venous blood glucose and lipids were measured.

Metabolic obesity was diagnosed if two risk factors out of five (high waist circumference, high blood pressure, elevated blood glucose, raised serum triglycerides, or low high-density lipoprotein (HDL) cholesterol) were present.

After that, four subgroups were identified - metabolically healthy non-obese (MHNO), metabolically healthy obese (MHO), metabolically obese non-obese (MONO), and metabolically obese obese (MOO). Of the individuals studied, 43.3 per cent were MONO, 28.3 per cent MOO, 26.6 per cent MHNO, and only 1.8 per cent MHO.

While physical inactivity and family history of diabetes were higher in MHO and MOO, smoking rates were higher in MHNO and MONO. Compared to the reference group (MHNO), MOO reported significantly lower intake of fruits and vegetables. The study also found that MOO showed the highest risk for T2D and CAD.

It cited a recent study by ICMR-INDIAB, which documented that “there are an alarming 254 million and 351 million adults with generalised and abdominal obesity, respectively, in India”.

The study added that MONO has a distinct phenotype (observable physical properties) with adverse metabolic consequences, highlighting the need to shift from body weight-focused approaches to broader strategies to identify and tackle non-communicable diseases.