Multiple Levels of Social Disadvantage and Links to Obesity in Adolescence and Young Adulthood

There is a strikingly high prevalence of adolescent obesity among underprivileged groups, including racial/ethnic minorities and those living in households affected by poverty and low levels of education.1 These vulnerable populations of adolescents not only contend with disadvantage at the family level, but also at the peer-group, neighborhood, and school level. For example, disadvantaged adolescents navigate environments where their classmates and friends may also be disadvantaged,2 leading to reinforcement of unhealthy behaviors.3 They may attend disadvantaged schools with less access to physical education programs or healthy foods.4 Finally, they may live in disadvantaged neighborhoods that do not have grocery stores that provide affordable fruits and vegetables and lack safe recreation sites to support physical activity.5 These factors warrant the consideration of multiple levels of disadvantage to understand the role of disadvantage on obesity during this period. The ecological model of human development emphasizes that individuals are influenced by the environments in which they are embedded, including the family, peer-group, neighborhood, and school.6 These environments are conceptualized as nested systems and represent increasingly larger contexts of the social environment in which adolescents live, learn, mature and interact with others. They impact available resources and opportunities, relationships and ties to others, and are subject to accepted norms of behavior.7 All levels operate together to influence adolescent development, including health behaviors and health status such as obesity. Although there is a body of research linking family, peer, neighborhood and school contexts to obesity in childhood and adolescence, prior research has not examined all of these contexts simultaneously.8-17 Furthermore, most research has utilized cross-sectional rather than longitudinal data, overlooking how these relationships may change over time.18 Because social disadvantage in one context is correlated with disadvantage in multiple contexts and across time, to fully understand how socioeconomic disadvantage is related to obesity requires modeling multiple levels of disadvantage across the early life course.19,20 Adolescence and young adulthood are critical stages in the life course during which lifestyle and health-related behaviors are established and the risk of obesity is high.21-23 Socioeconomic disparities in obesity increase dramatically during these periods and often persistent into later adulthood, disproportionately impacting the likelihood of chronic disease and further compounding economic well-being for disadvantaged populations.24-28 Adolescence and young adulthood are life stages when young people have more autonomy and control in decision-making regarding their behaviors, including those related to their health, and are especially influenced by the expanding social environments in which they are embedded.19 Our objective was to investigate the unique influence of various levels of social disadvantage simultaneously, using nationally representative longitudinal data. We created measures of socioeconomic disadvantage across multiple contexts, including the family, peer, school and neighborhood, and used multilevel modeling, a methodology that allows for the simultaneous examination of the effects of group-level and individual-level predictors29 to determine what levels of context were significantly associated with obesity during adolescence and young adulthood. This study contributes to the literature by modeling multiple levels of disadvantage and its relationship to obesity across the early life course. It also serves to ascertain the contexts most salient to obesity in early life. A better understanding of the social contexts in which adolescents are embedded and how they are associated with obesity may point the field to where opportunities for interventions are relatively more strategic to reduce the risk of obesity in adolescence and young adulthood.