Friendships and Risk of Over-weight among Diverse-origin Adolescents

描述（由申请人提供）：儿童肥胖的增加是全世界关注的公共卫生问题。在美国，17.6%的青少年在他们的年龄中具有高bmi。生命早期的肥胖与较差的身心健康和社会福祉有关，包括呼吸问题、2型糖尿病的早期发病、抑郁和社会排斥，并与成人肥胖和晚年慢性病的风险增加有关。这项研究探讨了一个对青少年肥胖风险的潜在重要影响，但在文献中没有得到足够的重视：友谊。目的：以青少年为研究对象，拟开展的研究将：1)确定体重与友谊形成的关系；2)从亲密度和持续时间方面探讨体重与友谊强度之间的关系；3)检查朋友是否影响体重相关行为，体重随时间的变化，以及这种影响发生的机制。本应用程序的另一个创新方法是考虑体重状况和友谊之间的关系如何因性别、种族/民族和移民身份而不同。设计：本项目将使用全国青少年健康纵向研究（Add Health）进行二次数据分析，这是一项具有全国代表性的青少年纵向调查。Add Health的独特设计允许研究人员将受访者的记录与他们的同学的记录联系起来，这样他们的体重和健康行为轨迹就可以在他们的家庭、学校和社区环境中考虑到——这比大多数依赖于受访者对他们朋友的说法的研究有一个优势。另一个优势是数据的纵向收集，这使我们能够长期跟踪青少年。方法：本研究为理解友谊和体重状况之间的关系建立了一个概念性框架。采用经调查调整的多元线性和逻辑回归来评估体重状况对高中青少年友谊的重要性。被调查者的记录被联系起来，以检查体重状况对友谊回报的差异，并探索高中和7年后朋友体重和健康行为之间的影响模式。在可能的范围内，研究人员将采用纵向分析和工具变量来纠正未观察到的异质性和反向因果关系的偏差，以区分同质性和影响，并隔离因果关系的途径。意义：了解社会环境与肥胖风险之间的关系，可以为健康行为的社会方面的研究和干预提供信息，并有可能利用社会网络改善年轻人的健康和健康行为。如果体重是建立友谊的一个重要因素，并且朋友们会一起参与与体重有关的行为，那么识别并利用这些关系的干预措施可能会更成功地带来行为改变。迄今为止，还没有一项研究能在全国范围内提供如此全面的青少年肥胖情况。公共卫生相关性：儿童肥胖的流行对制定促进健康身体比例和健康行为的干预措施提出了挑战，了解友谊的影响对制定这些干预措施很重要。这项提议的研究将进一步了解青少年肥胖风险和友谊之间的关系。我们的研究结果将为以下方面的研究和政策提供信息：(a)友谊在多大程度上影响儿童的健康行为和体重；(b)将朋友和同伴纳入预防和扭转美国青少年肥胖的干预措施的重要性。

DESCRIPTION (provided by applicant): Increases in childhood obesity are a public health concern worldwide. In the U.S., 17.6 percent of adolescents have high BMIs for their age. Obesity early in life is associated with poorer physical and mental health and social wellbeing, including respiratory problems, early onset of type 2 diabetes, depression, and social exclusion, and with adult obesity and increased risk of chronic disease later in life. This study explores a potentially important influence on obesity risks in adolescence that has not received sufficient attention in the literature: friendships. OBJECTIVES: Focusing on adolescents, the proposed research will: 1) determine how weight relates to friendship formation; 2) explore the relationship between weight and the strength of their friendship in terms of closeness and duration; and 3) examine whether friends influence weight-related behaviors, weight change in each other over time, and mechanisms through which this influence takes place. An additional innovative approach of this application is to consider how the relationship between weight status and friendships differs between youths by gender, race/ethnicity, and immigrant status. DESIGN: This project will perform secondary data analyses using the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative longitudinal survey of adolescents. The unique design of Add Health allows researchers to link respondents' records with those of their schoolmates so that the trajectories of weight and health behaviors of both can be considered within their family, school, and neighborhood contexts -an advantage over most studies, which rely on respondents' claims about their friends. Another advantage is the longitudinal collection of data, which allows us to follow adolescents over time. METHODS: The study develops a conceptual framework for understanding the relationships between friendships and weight status. Survey-adjusted multivariate linear and logistic regressions will be used to assess the importance of weight status for adolescents' friendship in high school. Respondent records are linked to examine differences in friendship reciprocation by weight status and to explore the patterns of influence between friends' weights and health behavior in high school and 7 years later. To the extent possible, researchers will employ longitudinal analyses and instrumental variables to correct biases of unobserved heterogeneity and reverse causality, to distinguish between homophily and influence, and to isolate pathways of causality. SIGNIFICANCE: Understanding the relationships between the social environment and obesity risks can inform research and interventions about the social aspects of health behavior and the potential for tapping social networks to improve health and healthy behaviors in young people. If weight is an important factor in the creation of friendships and friends engage in weight-related behaviors together, interventions that recognize and make use of these relationships may be more successful at bringing about behavior change. No study to date has provided such a comprehensive picture of adolescent obesity at the national level. PUBLIC HEALTH RELEVANCE: The prevalence of obesity among children poses a challenge to develop interventions that promote healthy body proportions and healthy behaviors, and understanding the influences of friendships is important for developing these interventions. The proposed study will further current understanding of the ways in which adolescents' obesity risks and friendships are intertwined. Our findings will inform research and policy about: (a) the extent to which children's health behavior and weight are shaped by friendships; and (b) the importance of incorporating friends and peers into interventions to prevent and reverse obesity among American youths.