“…Typically, the predictive relationships for BMR have r 2 values in the range from 60 to 70% (reviewed by Shetty et al, 1996) leading to residual errors averaging 600-900 kJ (coefficient of variation 8-12%) (e.g., Jequier and Schutz, 1981;Dallosso and James 1984;Soares and Shetty, 1986;Weyer et al, 2000). Studies employing more direct analyses of body composition, by for example dual energy X-ray absorptiometry, at the same time as BMR measurements, have revealed that the major predictor of BMR is fat-free mass (FFM) (Fukagawa et al, 1990;Cunningham 1991;Weinsier et al, 1992), and this explains approximately 70% of the total variation, with some studies finding a secondary, independent contribution of fat mass (FM) (Nelson et al, 1992;Svendsen et al, 1993). Because the 'Schofield equation' only includes body weight and height as predictors, with sex and age being accommodated by a series of different equations for various subgroups, the important roles played by FFM and FM in the determination of BMR raise the possibility that additional anthropogenic measures (such as circumferences or skinfolds) might enhance predictability, with a relatively trivial increase in the workload involved in the predictor measurements (Shetty et al, 1994).…”