Identifying Mechanisms of Peer Influence on Youth Weight-Related Behaviors

摘要 自20世纪70年代S以来，美国的儿童肥胖率增加了两到三倍。到目前为止， 以学校为基础的预防和治疗超重和肥胖的干预措施只取得了有限的成功。 其中许多干预措施都是由健康行为理论和改变战略来指导的，这些战略解决了 来自多个层面的影响。然而，关于同伴对青少年的影响的信息有限 体重状况和与体重相关的行为，如体力活动、屏幕时间和饮食模式。一个 越来越多的文献表明，这种与体重相关的行为在朋友之间是相似的，但 这种行为集群背后的机制尚不清楚。朋友可能会相互影响，但也 相似的学生可能会成为朋友，或者朋友可能会受到相似的外部影响。更好的 对这些现象的理解将有助于设计更有效的干预措施，从而利用 同辈影响力的力量。因此，这项拟议的研究的目的是确定这些机制 通过收集和分析社会网络和体重相关的行为数据在不同的年轻人队列中采取行动 初中生(6至8年级)。我们将清楚地衡量 互动(受访者与之共度时光的人)、情绪(受访者喜欢的人)以及 有组织的活动(班级、俱乐部和团队)。每学年将收集几次数据。 使我们能够以精细的时间粒度分析这些过程，并在有组织的 关于社会网络结构和权重相关的自然实验和准实验活动 行为。将使用面向随机行为者的模型来严格分析网络的协同进化 与结构和体重相关的行为。使用这些统计分析的结果，基于代理 (模拟)将开发包含直接因果关系和反馈的模型，以及 随着时间的推移，这些效应的形状。这样的模型将被用来模拟潜在的干预情景 行为，最终，体重状况。拟议的研究将确定独特的杠杆点 WRB干预的目标和时机。我们预计，下一代WRB干预措施将能够 使用从这项研究中获得的信息来提高他们防止青少年超重增加的能力 从而减少相关健康风险因素和共病的当前和未来流行率。该项目 将产生一个经过经验校准的试验台，用于开发、测试和评估干预策略， 这些数据可以与受隐私保护的研究数据一起与普通公众共享。

Summary The United States has experienced a two to three fold increase in pediatric obesity since the 1970’s. To date, school-based interventions to prevent and treat overweight and obesity have realized only limited success. Many of these interventions are guided by health behavior theories and change strategies that address the issue from multiple levels of influence. There is, however, limited information regarding peer influence on youth weight status and weight-related behaviors, such as physical activity, screen time, and dietary patterns. A growing body of literature suggests that such weight-related behaviors are similar among friends, but the mechanisms underlying this clustering of behaviors remain unclear. Friends may influence each other, but also similar students may become friends, or friends may be exposed to similar outside influences. A better understanding of these phenomena would facilitate design of more effective interventions that can leverage the power of peer influence. Therefore, the purpose of this proposed study is to identify these mechanisms of action by collecting and analyzing social network and weight-related behavior data in a cohort of diverse young adolescents during their middle school years (6th to 8th grade). We will distinctly measure networks of interaction (whom the respondent spends his/her time with), sentiments (whom the respondent likes), and organized activities (classes, clubs, and teams). Data will be collected several times each academic year allowing us to analyze these processes in fine time grain and to use external changes in the organized activities as natural experiments and quasi-experiments on social network structures and weight-related behaviors. Stochastic Actor-Oriented Models will be used to rigorously analyze the co-evolution of the network structure and weight-related behaviors. Using findings from those statistical analyses, Agent-Based (simulation) Models will be developed to incorporate direct causal relationships and feedbacks as well as the shapes of these effects over time. Such models will be used to simulate potential intervention scenarios on the behaviors and ultimately, weight status. The proposed research will identify unique leverage points for targeting and timing of WRB interventions. We anticipate that next generation WRB interventions will be able to use the information obtained from this study to improve their ability to prevent excess weight gain in youth thereby reducing the current and future prevalence of related health risk factors and co-morbidities. The project will produce an empirically calibrated test bed for developing, testing, and evaluating intervention strategies, which can be shared with the general public along with privacy-protected study data.