Estimating the energy gap among US children: A counterfactual approach
Estimating the energy gap among US children: A counterfactual approach
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DOI：
10.1542/peds.2006-0682
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发表时间：
2006-12-01
期刊：
影响因子：
8
通讯作者：
Kuntz, Karen M.
中科院分区：
文献类型：
--
作者：
Wang, Y. Claire;Gortmaker, Steven L.;Kuntz, Karen M.
OBJECTIVE.我们的目标是量化1988-1994年和1999- 2002年期间美国儿童体重增加的能量不平衡程度。我们采用了一种反事实的方法来估计体重增加超过正常增长和隐含的“能量差距”-每日能量摄入和支出之间的不平衡。在疾病控制和预防中心生长图表的基础上，我们构建了1988-1994年全国健康和营养检查调查（N = 5000）中2 - 4岁和5 - 7岁队列的体重、身高和BMI百分位数分布。在反事实的“仅正常生长”情景下，我们假设这些百分位数分布与10岁的队列保持相同。在这种假设下，我们根据基线年龄别体重和年龄别身高分布预测了该队列12 - 14岁和15 - 17岁的体重和身高分布。我们将这些分布与1999-2002年全国健康和营养检查调查（N = 3091）中相应年龄组的分布进行了比较，该调查与1988-1994年全国健康和营养检查调查后10年的情况相似。我们计算了反事实和观察到的体重分布之间的差异，并将此差异转化为估计的平均能量差，调整了归因于体重增加的总能量消耗。此外，我们估计了1999-2002年全国健康和营养检查调查中超重青少年累积的平均超重体重，通过分析全国青年纵向调查和博加卢萨心脏研究的纵向数据验证了我们的反事实假设。与反事实假设相比，1988-1994年全国健康和营养检查调查中2至7岁的男孩和女孩在10年期间平均每年多增重0.43公斤。假设3500千卡导致平均1磅的体重增加作为脂肪，我们的研究结果表明，减少110-165千卡/天的能量差距可以防止这种增加。在1999-2002年12 - 17岁的超重青少年中，结果表明，平均能量不平衡范围为678 - 1017千卡/天，因为10年来累积了26.5公斤。对造成儿童体重分布最近变化的能量不平衡进行量化，可以为人口干预提供突出的目标。平均每天110至165千卡的持续行为变化可能足以抵消能量差距。改变过量的饮食摄入（例如，消除一种每罐150千卡的含糖饮料）可能比增加体力活动水平（例如，一个30公斤的男孩用1.9小时的步行代替1.9小时的坐着，额外增加150千卡）更容易实现。体重增加水平较高的年轻人可能需要改变多种行为和环境，以缩小能量差距。
OBJECTIVE. Our goal was to quantify the magnitude of energy imbalance responsible for the increase in body weight among US children during the periods 1988-1994 and 1999-2002.METHODS. We adopted a counterfactual approach to estimate weight gains in excess of normal growth and the implicit "energy gap"-the daily imbalance between energy intake and expenditure. On the basis of Centers for Disease Control and Prevention growth charts, we constructed weight, height, and BMI percentile distributions for cohorts 2 to 4 and 5 to 7 years of age in the 1988-1994 National Health and Nutrition Examination Survey (N = 5000). Under the counterfactual "normal-growth-only" scenario, we assumed that these percentile distributions remained the same as the cohort aged 10 years. Under this assumption, we projected the weight and height distributions for this cohort at 12 to 14 and 15 to 17 years of age on the basis of their baseline weight-for-age and stature-for-age percentiles. We compared these distributions with those for corresponding age groups in the 1999-2002 National Health and Nutrition Examination Survey (N = 3091) similar to 10 years after the 1988-1994 National Health and Nutrition Examination Survey. We calculated differences between the counterfactual and observed weight distributions and translated this difference into the estimated average energy gap, adjusting for increased total energy expenditure attributable to weight gain. In addition, we estimated the average excess weight accumulated among overweight adolescents in the 1999-2002 National Health and Nutrition Examination Survey, validating our counterfactual assumptions by analyzing longitudinal data from the National Longitudinal Survey of Youth and Bogalusa Heart Study.RESULTS. Compared with the counterfactual scenario, boys and girls who were aged 2 to 7 in the 1988-1994 National Health and Nutrition Examination Survey gained, on average, an excess of 0.43 kg/year over the 10-year period. Assuming that 3500 kcal leads to an average of 1-lb weight gain as fat, our results suggest that a reduction in the energy gap of 110-165 kcal/day could have prevented this increase. Among overweight adolescents aged 12 to 17 in 1999-2002, results indicate an average energy imbalance ranging from 678 to 1017 kcal/day because of an excess of 26.5 kg accumulated over 10 years.CONCLUSIONS. Quantifying the energy imbalance responsible for recent changes in weight distribution among children can provide salient targets for population intervention. Consistent behavioral changes averaging 110 to 165 kcal/day may be sufficient to counterbalance the energy gap. Changes in excess dietary intake (eg, eliminating one sugar-sweetened beverage at 150 kcal per can) may be easier to attain than increases in physical activity levels (eg, a 30-kg boy replacing sitting for 1.9 hours with 1.9 hours walking for an extra 150 kcal). Youth at higher levels of weight gain will likely need changes in multiple behaviors and environments to close the energy gap.