Resting metabolic rate measured after subjects spent the night at home vs at a clinic

This study determined the effect on resting metabolic rate (RMR) of subjects spending the night before measurement at home vs at a clinic. Ten subjects participated in six randomized RMR measurements; three measurements were made after subjects slept the evening before the measurements in their home (H1, H2, and H3) and three after they slept in a clinical setting (C1, C2, and C3). There were no significant differences (P < 0.05) in oxygen consumption (VO2, mL/min), RMR (kJ/min, kJ.kg body wt-1.h-1, or kJ.kg fat-free mass-1.h-1), or respiratory exchange ratio (RER) between any of the six RMR measurements, or between mean values for the three home trials (VO2 = 216 +/- 41 mL/min, RER = 0.80 +/- 0.04, heart rate = 51 +/- 3 beats/min, ventilation = 7.1 +/- 1.1 L/min) vs the three clinical trials (VO2 = 216 +/- 45 mL/min, RER = 0.80 +/- 0.04, heart rate = 52 +/- 5 beats/min, ventilation = 7.0 +/- 1.1 L/min). We conclude that under most circumstances it is not important that subjects spend the night before RMR assessment at the measurement facility. However, when basal metabolic rate is to be assessed, an overnight stay at the clinical facility would generally be necessary.