Ball E J, O'Connor J, Abbott R, Steinbeck K S, Davies P S, Wishart C, Gaskin K J, Baur L A
James Fairfax Institute of Paediatric Nutrition, The Children's Hospital at Westmead, Westmead, NSW, Australia.
Am J Clin Nutr. 2001 Oct;74(4):524-8. doi: 10.1093/ajcn/74.4.524.
The recent worldwide increase in the prevalence of childhood obesity may be due in part to a decrease in children's physical activity levels.
The current study of children in the years just before puberty aimed to 1) measure total energy expenditure (TEE) by use of the doubly labeled water (DLW) method, 2) determine the proportion of TEE related to physical activity, 3) investigate the relations between measures of physical activity and body fatness, and 4) investigate possible sex differences in these relations.
The DLW technique was used to measure TEE over 10 d in 106 healthy children (52 boys) aged 7.8 +/- 0.9 y (x +/- SD). Fat-free mass, and hence fat mass, was derived from the (18)O dilution space. Resting energy expenditure (REE) was calculated with use of the Schofield equations. Physical activity level was calculated as TEE/REE.
Mean TEE in both boys (7871 +/- 1135 kJ/d) and girls (7512 +/- 1195 kJ/d) was significantly different (P < 0.0001) from FAO/WHO/UNU recommendations (13% and 9% lower, respectively). There was no significant difference in physical activity level between boys (1.69 +/- 0.22) and girls (1.71 +/- 0.23). In boys but not girls, physical activity level was inversely correlated with BMI (r = -0.37, P < 0.01), fat mass (r = -0.46, P < 0.005), and percentage of body fat (r = -0.50, P < 0.0001).
In boys but not girls, percentage of body fat is inversely associated with physical activity level. Physical activity is one factor contributing to body fatness in boys, but additional factors may influence the size of the fat stores in girls.
近期全球儿童肥胖患病率上升，部分原因可能是儿童身体活动水平下降。
当前针对青春期前几年儿童的研究旨在：1）使用双标水（DLW）法测量总能量消耗（TEE）；2）确定与身体活动相关的TEE比例；3）研究身体活动测量指标与体脂之间的关系；4）研究这些关系中可能存在的性别差异。
采用DLW技术对106名7.8±0.9岁（x±SD）的健康儿童（52名男孩）进行为期10天的TEE测量。通过（18）O稀释空间得出去脂体重，进而得出脂肪量。使用Schofield方程计算静息能量消耗（REE）。身体活动水平计算为TEE/REE。
男孩（7871±1135kJ/d）和女孩（7512±1195kJ/d）的平均TEE均显著低于粮农组织/世界卫生组织/联合国大学的建议值（分别低13%和9%，P<0.0001）。男孩（1.69±0.22）和女孩（1.71±0.23）的身体活动水平无显著差异。仅在男孩中，身体活动水平与BMI（r=-0.37，P<0.01）、脂肪量（r=-0.46，P<0.005）和体脂百分比（r=-0.50，P<0.0001）呈负相关。
仅在男孩中，体脂百分比与身体活动水平呈负相关。身体活动是导致男孩体脂增加的一个因素，但可能还有其他因素影响女孩脂肪储存量。
