Individual variations in basal metabolic rate and mechanical work efficiency in east java

Abstract

During the author's examination of individual variation in work output per unit energy intake in East Java in 1971, workers with low intakes were often as productive as workers with high intakes and the relative efficiency of the ten subjects with the lowest energy intakes was 80 percent higher than the high intake group. A selected sample of these same individuals was examined in greater detail in 1977 and the absolute range of variation in basal metabolic rate was almost 4:1. The average B.M.R. of the high energy group was twice that of the low energy group (P < 0.001) and the high intake subjects expended significantly more energy in performing standard work tasks. It was concluded that low energy intakes recorded in East Java may be related to both long‐term genetic adaptation and short‐term phenotypic adaptation with a decrease in B.M.R. playing a major role in facilitating a higher level of metabolic efficiency for energy stress subjects. Data clearly indicate that low levels of energy intake do not necessarily result in low levels of human performance.