Table 2.

Energy expenditure, activity, body temperature, and heart rate variability.

	12-h average				Preprandial period			Postprandial period
	n	24 °C	19 °C		24 °C	19 °C		24 °C	19 °C
Calorimetry
Energy expenditure (kcal/h)	21	82.09±8.61	86.98±9.93	P<0.001	77.94±8.58	83.38±9.67	P<0.001	86.70±9.31†	90.52±11.23†	P<0.001
Respiratory quotient	21	0.821±0.025	0.816±0.022	P=0.23	0.801±0.025	0.796±0.024	P=0.09	0.850±0.029†	0.843±0.026†	P=0.32
Activity
Wrist activity (activity counts)	22	69 442±35 806	72 434±36 999	P=0.97	27 402±14 167	30 823±18 040	P=0.41	27 798±16 436	26 884±15 159	P=0.39
Hip activity (activity counts)	21	3897±3709	3609±3248	P=0.50	1554±1247	1586±1417	P=0.82	1657±1846	1412±1464	P=0.21
Ankle activity (activity counts)	22	11 662±9563	10 690±6541	P=0.74	4324±3638	4384±2975	P=0.74	5691±7846	4917±4238	P=0.53
Body temperature
Core body temperature (°C)	10	36.90±0.24	36.87±0.25	P=0.56	36.79±0.28	36.82±0.22	P=0.92	37.04±0.22†	36.96±0.27	P=0.06
Neck temperature (°C)	17	35.12±0.59	34.05±1.05	P<0.001	34.96±0.64	33.82±1.15	P<0.001	35.28±0.63*	34.32±1.12†	P<0.001
Abdominal temperature (°C)	22	34.32±0.75	32.99±1.26	P<0.001	34.12±0.80	32.63±1.37	P<0.001	34.47±0.83*	33.40±1.31†	P=0.0016
Thigh temperature (°C)	21	32.62±0.74	30.63±1.68	P<0.001	32.39±0.79	30.39±1.58	P<0.001	32.93±0.90†	30.98±2.09	P<0.001
Heart rate variability
Heart rate (BPM)	20	65.26±6.98	62.33±8.72	P=0.004	61.89±7.17	59.52±7.95	P=0.029	68.78±7.68†	65.43±9.71†	P=0.005
Very low frequency HRV (ms2)	20	4146±1808	5432±3086	P=0.0016	4803±2044	6311±3659	P=0.0034	3487±1826†	4413±2538†	P=0.14
Low frequency HRV (ms2)	20	1737±998	2233±1402	P=0.0038	1972±1166	2491±1599	P=0.0048	1485±777†	1938±1211†	P=0.021
High frequency HRV (ms2)	20	663±455	962±648	P=0.001	744±451	1056±702	P=0.0043	575±507*	837±653†	P=0.0043

^*P<0.05 compared with preprandial period of the same day.

^†P<0.01 compared with preprandial period of the same day.