DAILY ENERGY-EXPENDITURE OF WOMEN BY FACTORIAL AND HEART-RATE METHODS

To compare the minute-by-minute heart rate (Flex-HR) reference method with the factorial method, total daily energy expenditure (TDEE) and t he pattern of daily energy expenditure (EE) were measured in nonpregna nt, nonlactating women 19-40 yr of age, working at their household cho res (at home, N = 20) or for remuneration in various kinds of employme nt (at work, N = 28). The factorial method used three data sets descri bed in the compendium of Ainsworth et al. (CMD), FAO/WHO/UNU (FAO), an d James and Schofield (J&S). Measurements were repeated on three round s separated by 3 months. The TDEE by Flex-HR method, by round, was 9.0 +/- 2.6, 8.9 +/- 1.4, and 10.3 +/- 3.4 MJ.d(-1) in the women at home and 9.7 +/- 2.3, 11.4 +/- 3.2, and 11.3 +/- 3.6 MJ.d(-1) in the women at work. Values using the CMD data set were not significantly differen t from Flex-HR in either group in any round, but FAO and J&S data sets gave significantly lower values than both of the former methods in al l rounds. The same statistical results were obtained for the patterns of activity. Since the timing of activities by the observers was the s ame, it is concluded that the major source of error in applying the fa ctorial method is in the values for energy expenditure assigned to the various activities and the ability of investigators to properly judge EE from available data sets.