Adult resting energy expenditure (REE) scales as height^~1.5 while body weight (BW) scales as height^~2. Mass-specific REE (i.e., REE/BW) is thus lower in tall subjects compared to their shorter counterparts, the mechanism of which is unknown. We evaluated the hypothesis that high metabolic rate brain mass scales to height with a power significantly less than that of BW, a theory that if valid would provide a potential mechanism for height-related REE effects. The hypothesis was tested by measuring brain mass on a large (n=372) post-mortem sample of Thai men. As brain mass-body size relations may be influenced by age, the hypothesis was secondarily explored in Thai men age 45 yrs (n=299) and with brain magnetic resonance imaging (MRI) studies in Korean men (n=30) age 20<30 yrs. The scaling of large body compartments was examined in a third group of Asian men living in New York (NY, n=28) with MRI and dual-energy x-ray absorptiometry. Brain mass scaled to height with a power (X±SEE; 0.46±0.13) significantly smaller (p<0.001) than that of BW scaled to height (2.36±0.19) in the whole group of Thai men; brain mass/BW scaled negatively to height (-1.94±0.20, p<0.001). Similar results were observed in younger Thai men and results for brain mass/BW vs. height were directionally the same (p=0.09) in Korean men. Skeletal muscle and bone scaled to height with powers similar to that of BW (i.e., ~2-3) in the NY Asian men. Models developed using REE estimates in Thai men suggest that brain accounts for most of the REE/BW height dependency. Tall and short men thus differ in relative brain mass but the proportions of BW as large compartments appear independent of height, observations that provide a potential mechanistic basis for related differences in REE and that have implications for the study of adult energy requirements.