Do state-level school nutrition requirements promote healthy eating and weight

描述（由申请人提供）：美国儿童肥胖的患病率处于历史最高水平，目前超过15%的儿童肥胖。儿童肥胖与较差的身体/心理健康和社会福利以及未来肥胖和心脏代谢疾病的风险增加有关。目的：我们将评估解决学校早餐和含糖饮料供应问题的国家政策的潜力，以改善小学和中学儿童的健康饮食和体重。我们检验了三个假设：1)州一级的学校早餐要求增加了学校早餐的供应和消费，增加了营养食品的摄入；2)国家限制在学校销售含糖饮料，导致这类饮料在学校的可得性降低，这些物品的总摄入量降低，儿童肥胖率降低；3)州级学校政策要求早餐和限制含糖饮料的销售对低收入和少数民族儿童的影响更大。设计：我们的分析策略复制了一项实验研究设计，根据儿童的居住状态，对是否暴露于政策变化的儿童进行了跟踪。比较在研究期间实施政策的州和未实施政策的州的儿童体重和消费量，使我们能够评估政策的效果。我们将使用幼儿纵向研究，1998-99年幼儿园班（ECLS-K），它跟踪了一个具有全国代表性的从幼儿园到八年级的儿童队列。ECLS-K包括大量少数民族和贫困儿童。我们检查了两组结果：儿童体重（BMI z-score和肥胖）和营养（早餐和含糖饮料的摄入）。ECLSK的一个显著优势是身高和体重是由训练有素的评估人员测量的。我们估计普通最小二乘回归、逻辑回归和固定效应模型，使用调查权重来确保代表性。我们的主要解释变量是州一级的政策，这些政策将被编译成一个综合数据集，并与ECLS-K数据合并。我们包括儿童、家庭、社区和学校特征的控制。我们根据种族/民族和贫困状况来估计模型。意义：要求改善学校营养的州法律可能为改善学龄儿童的营养和体重提供了一种简单、廉价的策略。然而，这些政策的有效性尚未得到探讨。这项研究有助于了解儿童时期的体重变化、肥胖的进展以及影响这些变化的行为和环境因素，评估：1)学校对国家政策变化的反应；2)国家政策对儿童体重和营养的影响；3)学生是否将不健康食品的消费转移到校外环境。我们将从测量儿童体重和身高的最大的全国纵向研究中提供有关这些问题的经验证据。

DESCRIPTION (provided by applicant): The prevalence of obesity among American children is at an all-time high, with over 15% of children currently obese. Child obesity is associated with poorer physical/mental health and social wellbeing as well as increased future risk of obesity and cardiometabolic disease. OBJECTIVES: We will evaluate the potential of state policies that address school breakfast and sweetened beverage availability to improve healthy eating and body weight in elementary and middle school children. We test three hypotheses: 1) State level school breakfast requirements increase availability and consumption of school breakfast and increase intake of nutritious foods; 2) State restrictions on sales of sweetened beverages at school lead to lower availability of such beverages at schools, lower total intake of these items, and lower prevalence of obesity among children; 3) State-level school policies requiring breakfast and restricting sweetened beverage sales have greater impact on low income and minority children. DESIGN: Our analytic strategy replicates an experimental study design by following children who were and were not exposed to policy changes, depending on their state of residence. Comparing children's weight and consumption in states that implemented a policy during the study with those that did not allows us to assess the effect of the policies. We will use the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K), which follows a nationally representative cohort of children from kindergarten into 8th grade. ECLS-K includes substantial numbers of minority and impoverished children. We examine 2 sets of outcomes: children's weight (BMI z-score and obesity) and nutrition (breakfast and sweetened beverage consumption). A significant advantage of the ECLSK is that height and weight are measured by trained assessors. We estimate ordinary least squares regressions, logistic regressions, and fixed effects models, using survey weights to ensure representativeness. Our key explanatory variables are state-level policies, which will be compiled into a comprehensive dataset and merged with the ECLS-K data. We include controls for child, home, neighborhood, and school characteristics. We estimate models by race/ethnicity and poverty status. SIGNIFICANCE: State laws requiring better school nutrition potentially offer a simple, inexpensive strategy for improving nutrition and weight among school-children. Yet the effectiveness of these policies has not been explored. This research contributes to knowledge about weight changes during childhood, progression to obesity, and behavioral and environmental factors that affect these, assessing: 1) The responsiveness of schools to state policy changes; 2) The influence of state policies on child weight and nutrition; and 3) Whether students displace their consumption of unhealthy goods to out-of school settings. We will provide empirical evidence on these issues from the largest national longitudinal study measuring weight and height in children. Public Health Relevance: Previous research shows that breakfast and soda consumption are both independently associated with children's weight outcomes, suggesting that interventions focused on these may have long-term benefits for child health. This study will evaluate state policies with high potential to improve healthy eating and body weight among children, measuring the effects of state policies that require schools to offer breakfast and that restrict sales of sweetened beverages at school. This policy evaluation will assist policymakers in making informed decisions about whether more widespread legislation in these areas would promote children's health.