One of the more charged words in English, often eliciting strong emotional reactions, is obesity. Medically, its dispassionate purpose is to help determine when interventions should be implemented to prevent life-threatening comorbidities, especially diabetes, that typically accompany excess adiposity. 1 Haw JS Galaviz KI Straus AN et al. Long-term sustainability of diabetes prevention approaches: a systematic review and meta-analysis of randomized clinical trials.

JAMA Intern Med. 2017; 177: 1808-1817

Hence, the definition of obesity carries important clinical and policy implications. Three decades ago, WHO defined obesity as a BMI of 30 kg/m2 or more on the basis of studies in White populations quantifying relationships between BMI and mortality. 2 WHO
Physical status: the use and interpretation of anthropometry. Subsequent evidence showed that Asian individuals are susceptible to diabetes at lower BMIs than White individuals. 3 WHO expert consultation
Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies.

Lancet. 2004; 363: 157-163

This finding prompted WHO and the National Institute for Health and Care Excellence to define a BMI of 27·5 kg/m2 or more as the cutoff for obesity among south Asian and Chinese populations. 3 WHO expert consultation
Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies.

Lancet. 2004; 363: 157-163

, 4 Universal cut-off BMI points for obesity are not appropriate.

Br J Nutr. 2001; 85: 135-136

, 5 National Institute for Health and Care Excellence
BMI: preventing ill health and premature death in black, Asian and other minority ethnic groups. Public health guideline [PH46]. Although this addition was logical, it arose from sparse data. Their recommendations also do not consider data from other ethnicities, such as Black and Arab populations.