Equilibrium Energy Intake Estimated by Dietary Energy Intake and Body Weight Changes in Young Japanese Females

Abstract

431Estimated energy requirement (EER) for the Japanese is defined as energy intake (EI) required to maintain body weight (1). However, EER is actually determined by measuring energy expenditure (EE). Although the units of EI and EE are the same (kcal), they are measured differently. EI is calculated based on the weight of food consumed and its energy content as it appears in the Food Composition Tables (2). EE is determined mainly by measurement of oxygen intake.There is no confirmation that EE and EI are the same, but the current guidelines for EI treat them as such (1). Thus, the present study sought to compare EE and EI to establish the relationship between the two.In adults, it should be possible to determine EER using EI if EI and body weight change are significantly correlated. Therefore, in a previous study (3), we tested this relationship using data from prior human metabolic balance studies in which male subjects consumed diets with known energy content and had their body weights recorded. Although the number of the subjects was small, the relationship between EI and body weight change was significant.In this analysis, we sought to confirm this relationship in a larger cohort of female subjects using data from human metabolic balance studies. SUBJECTS AND METHODSData for this analysis were obtained from 17 human metabolic balance studies (n5178) conducted by the National Institute of Health and Nutrition (Tokyo) between 1986 and 2007. Some of results in minerals and nitrogen were already reported (4-21). However, the relationship between EI and body weight change in female subjects was analyzed in this report for the first time. Three of these studies were omitted from the present analysis, two because they used male subjects, and one which did not collect skin-fold thickness data. Subjects in the remaining studies (14 experiments, n5149) were young females. In four and a half studies (n543), sweat was collected from the arm to estimate loss of minerals through sweating during exercise using a bicycle ergometer (intensity: 1.0-1.5 kp, velocity: 50-60 rpm, duration: 30-60 min/trial, once or twice per day, with room temperature 22-29˚C and humidity 40-65% RH) (4); these subjects were classified in the exercise group Summary To determine the energy intake (EI) required to maintain body weight (equilibrium energy intake: EEI), we investigated the relationship between calculated energy intake and body weight changes in female subjects participating in 14 human balance studies (n5149) conducted at the National Institute of Health and Nutrition (Tokyo). In four and a half studies (n543), sweat was collected from the arm to estimate loss of minerals through sweating during exercise on a bicycle ergometer; these subjects were classified in the exercise group (Ex G). In nine and a half experiments (n5106) subjects did not exercise, and were classified in the sedentary group (Sed G). The relationship between dietary energy intake (EI) and body weight (BW) changes (DBW) was analyzed and divided by four variables: b...