REAPPEARANCE TEST OF THE POST-ABSORPTIVE RESTING METABOLIC RATE IN YOUNG JAPANESE FEMALES

Abstract

The purpose of this study was to investigate the reappearance of the post-absorptive resting metabolic rate (PARM) during a prescribed diet. The subjects were 10 sedentary female college students (20.1±0.7yrs) . Thyroid function was judged in all of them to be within a normal range. Subjects stayed in a metabolic ward at the National Institute of Health and Nutrition for 18 days. The post-absorptive resting metabolic rate was measured 4 times during the experimental period. Moreover, blood was collected five times, and general health care including the measurement of thyroxin by blood biochemical examination was carried out. As for the actual metabolic measurements, a high reappearance was confirmed by the intra-individual coefficient of variation (CV) of the post-absorptive resting metabolic rate (3.5±1.8%) and the inter-individual CV (7.2%) . The smallest CV was the standard value of PARM/body surface area, followed by PARM/body weight, PARM/LBM, and PARM/urine creatinine. On the other hand, weight (50.8±4.9 vs 50.3±4.6 kg ; p<0.01), hemoglobin concentration (13.7 ± 0.5 vs 12.8±0.5g/dl ; p<0.05), serum total cholesterol level (194±41 vs 175 ± 37 mg/dl ; p<0.05) and post-absorptive resting oxygen uptake (0.149±0.01 vs 0.142±0.011/min ; p<0.01) decreased significantly during the experiment. According to the Japanese Recommended Dietary Allowances (RDAs) (1999), basal metabolic rate (BMR) was calculated at 1, 210 kcal/day or 23.6 kcal/kg body weight/day for women within the 18-29 year age group. But the results (the mean of all measurements) of this research suggested that this value was 1, 033 ± 79 kcal/day, or 20.7 ± 2.0 kcal/kg body weight/day based on the method of Weir ; and was approximately 10% lower than RDAs. Future investigation is required to explain the reasons for the difference in BMR between this study and that of previous ones.