Can obesity affect daily living activities energy expenditure in children?

Differences between obese and non-obese children have been already measured by indirect calorimetry for resting energy expenditure (REE). On the contrary no study investigated on the variation of activity energy expenditure (AEE) other than walking and running. The aim of the present study was to determine the REE and the AEE of 11 common physical activities in overweight or obese (G1) and non-obese (G2) children. 21 volunteer children participated in the study (G1: N=10, age, 9.5±1.6 yr; BMI, 23.6±1.7 kg/m2; VO2max, 33.6±1.6 ml/kg/min; G2: N=11, age, 9.4±1.6 yr; BMI, 16.5±1.6 kg/m2; VO2max, 45.6±1.6 ml/kg/min). Subjects were classified as overweight, obese and non-obese according to international reference values (Cole, 2000). Two sets of activities were performed in two separate days by each subject. Activities ranged from crayoning to running and rope skipping and were divided according to the actual intensity (<3 METS, 3-6 METS, >6 METS). Oxygen consumption was measured continuously with a portable metabolic system (K4b2, Cosmed, Italy). REE was higher, even if not significantly, in G1 in comparison with G2 (REE: G1 1204.7±549.8 kcal/d, G2 1046.3±303.2 kcal/d). No significant differences were detected between G1 and G2 in AEE, even if the same trend that REE was observed for moderate and vigorous activities (AEE <3 METS: G1 58.5±23.5 kcal/d, G2 63.2±22.3 kcal/d; AEE 3-6 METS: G1 180.8±65.2 kcal/d, G2 170.1±54.9; AEE >6 METS: G1 331.7±101.6 kcal/d, G2 312.9±97.3 kcal/d). These data indicate that REE and moderate and vigorous AEE are energetically more expensive for overweight and obese children than for non-obese children, even if this difference is not statistically significant. These data confirm that obese children show a trend to a higher energy expenditure, the mechanical power being equal. Devising a physical activity program in which obese children train together with non-obese children could be useful and effective in the treatment of overweight or obesity. Rodriguez G et al. J Physiol Biochem. 2002 Mar;58(1):9-15. Maffeis C et al. J Pediatr. 1993 Aug;123(2):193-9. Cole TJ et al. BMJ. 2000 May 6;320(7244):1240-3.