This paper reviews the most relevant aspects of measuring basal metabolic rate (BMR). The authors discuss individual and lifestyle factors (age, anthropometry, smoking, physical activity, diet, menses, and ethnicity) as well as possible environmental factors at time of measurement which may alter BMR values. Various available predictive equations, especially those recommended by the World Health Organization in 1985, and subsequent validation studies, particularly in populations living in the tropics, are presented. The review indicates the need for more information on BMR from populations living in different parts of the world so that better estimates can be provided for clinicians and epidemiologists.