We read with interest the study by Bahler et al.  that discusses the findings observed in two studies comparing brown adipose tissue (BAT) activity and volume in healthy young white Caucasians and South Asians [2,3]. While Admiraal et al.  found no differences in BAT activity and volume between groups, Bakker et al.  reported lower BAT volume in South Asians, despite the fact that both studies were comparable in terms of age, body mass index, sex, ethnicity and country of the participants.