School Meals and BMI Percentile: Secondary Analyses of Non-Self-Report Data

描述(由申请人提供)：有人担心，参加食品援助计划可能与肥胖有关，因为许多肥胖者都受到此类计划的服务。2004年3月召开的一个专家小组没有发现儿童肥胖与参加学校早餐计划(SBP)和国家学校午餐计划(NSLP)之间存在关联的一致证据。该小组建议的调查方法包括1)利用自然机会进行对照试验；2)在现有研究的基础上增加体重、身高和参与计划；3)启动针对特定人群的较小规模研究；以及4)使用现有的数据集来了解关系。方法4的数据集可从2005年8月结束的R01 HL063189获得。发表的一项小型研究结果表明，观察到的(但不是自我报告的)高BMI的四年级学生在学校膳食中的能量摄入量(第85个百分位数)高于低BMI的儿童(第e5和50个百分位数)。对另一项研究数据的初步分析未发表的结果进一步证明，观察到的学校膳食能量摄入量随四年级儿童BMI百分位数的不同而不同，但在分析自我报告的能量摄入量时，结果有所不同。我们现在提出一个为期两年的项目，使用来自R01 HL063189的4项研究的四年级儿童的数据。目的1是调查SBP和NSLP参与与儿童肥胖之间的可能关系。我们有1,542名儿童(黑人占51%，白人占49%，女孩占51%)在四年级参加SBP和NSLP的姓名标签记录(汇编时间平均为10至34天)。目标1有两个研究问题(RQ)，分别针对四个研究和合并：RQ1-BMI百分位数和SBP和四年级NSLP参与之间的关系是什么，以及这种关系是否有a)单独参与SBP和NSLP与组合，b)性别，c)种族？RQ2-与姓名标签记录相比，父母在同意书上对儿童SBP和/或NSLP参与的回答有多准确，这是否因BMI百分位数、性别和种族而不同？当使用父母的反应时，RQ1有什么不同？目标2是检查一部分儿童的行为和选择，以了解实际(观察到的)学校膳食摄入量的差异。对于子组，我们观察了344名儿童(54%是黑人，46%是白人，50%是女孩)吃1到3顿早餐和1到3顿午餐，总共1268顿学校餐(50%是早餐)。对于子集，目标2分别为4项研究提供了2个RQ，并将其合并：RQ3-BMI百分位数与学校膳食中观察到的能量摄入量之间的关系是什么，这是否存在以下差异：a)早餐和午餐分别与合并，b)性别，c)种族？RQ4-RQ3的差异在多大程度上是由a)标准分量的进食量，b)行业，c)牛奶口味/脂肪的选择，d)冷的(即食的谷类食品)与热的(如香肠饼干)早餐的选择，以及e)点菜冰淇淋？结果将为未来对照试验和/或队列研究的设计提供信息，以了解参与SBP和NSLP的儿童肥胖的途径。公共卫生相关性：参加学校早餐计划(SBP)和国家学校午餐计划(NSLP)可能与儿童肥胖有关，但之前的研究无法提供一致的关系的证据。该项目中的二次分析是有效和及时的下一步，因为结果将增加新的知识，并为未来对照试验和/或队列研究的设计提供信息，旨在了解参与SBP和NSLP的儿童肥胖的途径。我们现有的4个数据集独特地使我们能够使用非自我报告数据来调查身体质量指数(BMI)百分位数与SBP和NSLP参与之间的关系，以及按BMI百分位调查儿童在学校膳食中实际(观察到的)能量摄入量的差异，以及观察到的行为的各个方面和在学校膳食中选择食物/饮料的不同方面，这些数据集的特征包括：1542名儿童中每个人平均随机10至34天参与SBP和NSLP的姓名标签记录；344名儿童在学校膳食中的观察摄入量(来自观察者间可靠性的可接受结果)；和1,542名儿童的体重/身高测量(测量人员之间的可信度结果可接受)。

DESCRIPTION (provided by applicant): There is concern that participation in food assistance programs may be related to obesity because many obese individuals are served by such programs. An Expert Panel convened in 03/2004 found no consistent evidence of association between childhood obesity and participation in the School Breakfast Program (SBP) and National School Lunch Program (NSLP). That Panel recommended investigative approaches including 1) use natural opportunities for controlled trials; 2) add weight, height, and program participation to existing studies; 3) initiate smaller studies with specific populations; and 4) use existing data sets to understand relationships. Data sets for approach 4 are available from R01 HL063189, which ended in 08/2005. Published results from a small study indicated that observed (but not self-reported) energy intake at school meals was higher for 4th-grade children of high-BMI (e85th percentile) than low-BMI (e5th and <50th percentiles). Unpublished results from preliminary analyses of data from another study provide further evidence that observed energy intake at school meals varies by 4th-grade children's BMI percentile, but results differed when self-reported energy intake was analyzed. We now propose a 2-year project using data for 4th-grade children from 4 studies for R01 HL063189. Aim 1 is to investigate a possible relationship between SBP and NSLP participation and childhood obesity. We have nametag records (compiled on an average of 10 to 34 random days) of SBP and NSLP participation in 4th-grade for 1,542 children total (51% Black, 49% White; 51% girls). Aim 1 has 2 research questions (RQs) for the 4 studies separately and combined: RQ1 - What is the relationship between BMI percentile and SBP and NSLP participation in 4th grade, and does this differ a) for SBP and NSLP participation separately vs. combined, b) by sex, and c) by race? RQ2 - How accurate are parental responses on consent forms concerning children's SBP and/or NSLP participation compared to nametag records, and does this differ by BMI percentile, sex, and race? How does RQ1 differ when parental responses are used? Aim 2 is to examine behaviors and selections for a subset of children to understand differences in actual (observed) school-meal intake. For the subset, we observed 344 children (54% Black, 46% White; 50% girls) for 1 to 3 breakfasts and 1 to 3 lunches for 1,268 total school meals (50% breakfast). For the subset, Aim 2 has 2 RQs for the 4 studies separately and combined: RQ3 - What is the relationship between BMI percentile and observed energy intake at school meals, and does this differ a) for breakfast and lunch separately vs. combined, b) by sex, and c) by race? RQ4 - To what extent are RQ3 differences explained by a) amounts eaten of standardized portions, b) trades, c) milk flavor/fat selections, d) cold (i.e., ready-to-eat cereal) vs. hot (e.g., sausage biscuit) breakfast selection, and e) ` la carte ice cream? Results will inform the design of future controlled trials and/or cohort studies to understand pathways to obesity among children who participate in SBP and NSLP. PUBLIC HEALTH RELEVANCE: Participation in the School Breakfast Program (SBP) and National School Lunch Program (NSLP) may be related to childhood obesity, but previous research has been unable to provide evidence of a consistent relationship. The secondary analyses in this project are an efficient and timely next step because results will add new knowledge and inform the design of future controlled trials and/or cohort studies aimed at understanding pathways to obesity among children who participate in SBP and NSLP. Features of our 4 existing data sets that uniquely position us to use non-self-report data to investigate the relationship between body mass index (BMI) percentile and SBP and NSLP participation as well as differences in children's actual (observed) energy intake at school meals by BMI percentile along with various aspects of observed behaviors and food/beverage selections at school meals include the following: nametag records of SBP and NSLP participation on an average of 10 to 34 random days for each of 1,542 children; observed intake at school meals for a subset of 344 children (with acceptable results from inter- observer reliability); and weight/height measurements for 1,542 children (with acceptable results from inter- measurer reliability).