title: Leveraging social influence to address overweight and obesity using agent-based models: the role of adolescent social networks.
abstract: The prevalence of adolescent overweight and obesity (hereafter, simply "overweight") in the US has increased over the past several decades. Individually-targeted prevention and treatment strategies targeting individuals have been disappointing, leading some to propose leveraging social networks to improve interventions. We hypothesized that social network dynamics (social marginalization; homophily on body mass index, BMI) and the strength of peer influence would increase or decrease the proportion of network member (agents) becoming overweight over a simulated year, and that peer influence would operate differently in social networks with greater overweight. We built an agent-based model (ABM) using results from R-SIENA. ABMs allow for the exploration of potential interventions using simulated agents. Initial model specifications were drawn from Wave 1 of the National Longitudinal Study of Adolescent Health (Add Health). We focused on a single saturation school with complete network and BMI data over two waves (n = 624). The model was validated against empirical observations at Wave 2. We focused on overall overweight prevalence after a simulated year. Five experiments were conducted: (1) changing attractiveness of high-BMI agents; (2) changing homophily on BMI; (3) changing the strength of peer influence; (4) shifting the overall BMI distribution; and (5) targeting dietary interventions to highly connected individuals. Increasing peer influence showed a dramatic decrease in the prevalence of overweight; making peer influence negative (i.e., doing the opposite of friends) increased overweight. However, the effect of peer influence varied based on the underlying distribution of BMI; when BMI was increased overall, stronger peer influence increased proportion of overweight. Other interventions, including targeted dieting, had little impact. Peer influence may be a viable target in overweight interventions, but the distribution of body size in the population needs to be taken into account. In low-obesity populations, strengthening peer influence may be a useful strategy.
authors.affiliation: Department of Public Health Sciences, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Public Health Sciences, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
authors.forename: L
authors.initials: L
authors.lastname: Tong
authors.affiliation: Kellogg School of Management, Northwestern University, 2169 Campus Dr, Evanston, IL 60208, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Lamberson
authors.affiliation: Department of Public Health Sciences, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Durazo-Arvizu
authors.affiliation: Department of Public Health Sciences, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
authors.forename: A
authors.initials: A
authors.lastname: Luke
authors.affiliation: Department of Public Health Sciences, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA. Electronic address: dshoham@luc.edu.
authors.forename: D A
authors.initials: DA
authors.lastname: Shoham
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D015992:Body Mass Index; D005260:Female; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008962:Models, Theoretical; D050177:Overweight / Q000517:prevention & control* / Q000523:psychology; D063766:Pediatric Obesity / Q000517:prevention & control / Q000523:psychology; D010379:Peer Group; D012944:Social Support
keywords: Add health; Agent-based models; National longitudinal study of adolescent health; Obesity; Peer influence; Social networks; Stigma; USA