Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts.
Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York.
Am J Prev Med. 2022 Aug;63(2):242-250. doi: 10.1016/j.amepre.2022.02.016. Epub 2022 Apr 7.
The Supplemental Nutrition Assistance Program; Free/Reduced Priced Lunch Program; and Special Supplemental Nutrition Program for Women, Infants, and Children reduce food insecurity for millions of Americans with lower incomes. However, critics have questioned whether they increase obesity. This study examined whether program participation was associated with BMI z-score from kindergarten to fifth grade.
Data from 4,457 primary-grade students whose household incomes were equal to or below 200% of the federal poverty level from kindergarten to fifth grade as part of the Early Childhood Longitudinal Study, Kindergarten Class of 2010‒2011 were analyzed. Marginal structural models with inverse probability of treatment/censoring weights were used to estimate associations between Supplemental Nutrition Assistance Program/Free and Reduced Priced Lunch participation over time and fifth-grade BMI z-score, accounting for lost-to-follow-up and time-varying confounders. Weighted generalized estimating equations were used to examine associations between Special Supplemental Nutrition Program for Women, Infants, and Children participation and BMI z-score trends. All analyses incorporated sampling weights. The Early Childhood Longitudinal Study, Kindergarten Class of 2010‒2011 data were collected from 2010-2016; analyses were conducted in 2021 and 2022.
At baseline, 2,419 (54.3%) respondents participated in the Supplemental Nutrition Assistance Program, 3,993 (89.6%) participated in Free/Reduced Priced Lunch, and 3,755 (84.2%) reported past participation in the Special Supplemental Nutrition Program for Women, Infants, and Children. No associations were found between any program and fifth-grade BMI z-score or between Special Supplemental Nutrition Program for Women, Infants, and Children participation and BMI z-score trend.
Previous findings of relationships between program participation and BMI may have been because of weaker study designs and uncontrolled confounding. Participation in the Supplemental Nutrition Assistance Program; Free/Reduced Priced Lunch; and Special Supplemental Nutrition Program for Women, Infants, and Children was not associated with increased risk of childhood obesity in this recently conducted longitudinal study.
补充营养援助计划、免费/降价午餐计划和特殊补充营养计划为妇女、婴儿和儿童(WIC)为收入较低的数百万美国人减少了粮食不安全问题。然而,批评者质疑这些计划是否会导致肥胖。本研究调查了这些计划的参与是否与从幼儿园到五年级的 BMI z 分数有关。
从 2010-2011 年幼儿园纵向研究幼儿园班的 4457 名主要年级学生的数据中分析了其家庭收入等于或低于联邦贫困水平 200%的学生的数据。使用逆概率处理/删失加权的边际结构模型来估计补充营养援助计划/免费和降价午餐参与随时间与五年级 BMI z 分数的关联,同时考虑了随访损失和时变混杂因素。使用加权广义估计方程来检验 WIC 参与与 BMI z 分数趋势之间的关联。所有分析都纳入了抽样权重。2010-2016 年收集了幼儿园纵向研究幼儿园班 2010-2011 年的数据;分析于 2021 年和 2022 年进行。
在基线时,2419 名(54.3%)受访者参加了补充营养援助计划,3993 名(89.6%)参加了免费/降价午餐,3755 名(84.2%)报告过去参加过 WIC。在五年级 BMI z 分数或 WIC 参与与 BMI z 分数趋势之间,没有发现任何计划之间存在关联。
之前关于计划参与与 BMI 之间关系的发现可能是由于研究设计较弱和未控制的混杂因素所致。在最近进行的这项纵向研究中,参加补充营养援助计划、免费/降价午餐和 WIC 与儿童肥胖风险的增加无关。