Daily energy expenditure in free-living conditions in obese and non-obese children: comparison of doubly labelled water (2H2(18)O) method and heart-rate monitoring.
OBJECTIVE
To compare the heart-rate monitoring with the doubly labelled water (2H2(18)O) method to estimate total daily energy expenditure in obese and non-obese children.


METHODS
Cross sectional study of obese and normal weight children.


METHODS
13 prepubertal children: six obese (4M, 2F, 9.1 +/- 1.5 years, 47.3 +/- 9.7 kg) and seven non-obese (3M, 4F, 9.3 +/- 0.6 years, 31.8 +/- 3.2 kg).


METHODS
Total daily energy expenditure was assessed by means of the doubly labelled water method (TEEDLW) and of heart-rate monitoring (TEEHR).


RESULTS
TEEHR was significantly (P < 0.05) higher than TEEDLW in obese children (9.47 +/- 0.84 MJ/d vs 8.99 +/- 0.63 MJ/d) whereas it was not different in non-obese children (8.43 +/- 2.02 MJ/d vs 8.42 +/- 2.30 MJ/d, P = NS). The difference of TEE assessed by HR monitoring in the obese group averaged 6.2 +/- 4.7%. At the individual level, the degree of agreement (difference between TEEHR and TEEDLW +/- 2s.d.) was low both in obese (-0.36, 1.32 MJ/d) and in non-obese children (-1.30, 1.34 MJ/d). At the group level, the agreement between the two methods was good in nonobese children (95% c.i. for the bias:-0.59, 0.63 MJ/d) but not in obese children (0.04, 0.92 MJ/d). Duration of sleep and energy expenditure during resting and physical activity were not significantly different in the two groups. Patterns of heart-rate (or derived energy expenditure) during the day-time were similar in obese and non-obese children.


CONCLUSIONS
The HR monitoring technique provides an estimation of TEE close to that assessed by the DLW method in non-obese prepubertal children. In comparison with DLW, the HR monitoring method yields a greater TEE value in obese children.
Maffeis
C
C
Regional Center for Juvenile Diabetes, University of Verona, Italy.
Pinelli
L
L
Zaffanello
M
M
Schena
F
F
Iacumin
P
P
Schutz
Y
Y
D000886:Anthropometry; D015992:Body Mass Index; D002153:Calorimetry, Indirect; D002245:Carbon Dioxide / Q000378:metabolism; D002648:Child; D003430:Cross-Sectional Studies; D017666:Deuterium Oxide; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D009765:Obesity / Q000378:metabolism / Q000503:physiopathology*; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology
D002245:Carbon Dioxide; D017666:Deuterium Oxide; D010100:Oxygen