COMPARISON OF THE HEART RATE-MONITORING AND FACTORIAL METHODS - ASSESSMENT OF ENERGY-EXPENDITURE IN HIGHLAND AND COASTAL ECUADOREANS

Accurate estimates of total daily energy expenditure (TDEE) are critic al to studies of the nutritional adaptation of human populations. This study compared the standard factorial method with the recently develo ped flex-HR technique in a sample of 32 adults (16 males, 16 females) from rural, agricultural communities of highland and coastal Ecuador. Although energy expenditures obtained from the two methods were highly correlated (r = 0.759, P < 0.0001), the 1985 FAO/WHO/UNU factorial me thod significantly underestimated TDEE relative to the heart rate-moni toring technique (10.27 +/- 2.54 compared with 11.91 +/- 3.96 MJ/d, P < 0.001). The degree of underestimation was greater in males, who had higher energy expenditures. Similarly, underestimation was greater in the highland farmers, who were studied during a period of heavy agricu ltural work. The differences in energy expenditure estimates translate d into a 10% difference in estimated energy adequacy. Additional resea rch is needed to identify the potential sources of bias in the factori al method and to further develop other techniques for accurately estim ating energy expenditure under field conditions.