title: #Proana: Pro-Eating Disorder Socialization on Twitter.
abstract: Pro-eating disorder (ED) online movements support engagement with ED lifestyles and are associated with negative health consequences for adolescents with EDs. Twitter is a popular social media site among adolescents that provides a unique setting for Pro-ED content to be publicly exchanged. The purpose of this study was to investigate Pro-ED Twitter profiles' references to EDs and how their social connections (followers) reference EDs.
  
  
  
  A purposeful sample of 45 Pro-ED profiles was selected from Twitter. Profile information, all tweets, and a random sample of 100 of their followers' profile information were collected for content analysis using the Twitter Application Programming Interface. A codebook based on ED screening guidelines was applied to evaluate ED references. For each Pro-ED profile, proportion of tweets with ED references and proportion of followers with ED references in their own profile were evaluated.
  
  
  
  In total, our 45 Pro-ED profiles generated 4,245 tweets for analysis. A median of 36.4% of profiles' tweets contained ED references. Pro-ED profiles had a median of 173 followers, and a median of 44.5% of followers had ED references. Pro-ED profiles with more tweets with ED references also tended to have more followers with ED references (β = .37, p < .01).
  
  
  
  Findings suggest that profiles which self-identify as Pro-ED express disordered eating patterns through tweets and have an audience of followers, many of whom also reference ED in their own profiles. ED socialization on Twitter might provide social support, but in the Pro-ED context this activity might also reinforce an ED identity.
authors.affiliation: Department of Sociology, University of Washington, Seattle, Washington; Center for Child Health, Behavior and Development, Seattle Children's Research Institute, Seattle, Washington. Electronic address: arsena@g.ucla.edu.
authors.forename: Alina
authors.initials: A
authors.lastname: Arseniev-Koehler
authors.affiliation: Department of Sociology, University of Washington, Seattle, Washington.
authors.forename: Hedwig
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Sociology, University of Washington, Seattle, Washington; Department of Statistics, University of Washington, Seattle, Washington.
authors.forename: Tyler
authors.initials: T
authors.lastname: McCormick
authors.affiliation: Center for Child Health, Behavior and Development, Seattle Children's Research Institute, Seattle, Washington; Department of Pediatrics, University of Washington, Seattle, Washington.
authors.forename: Megan A
authors.initials: MA
authors.lastname: Moreno
mesh_terms: D000293:Adolescent; D000328:Adult; D001068:Feeding and Eating Disorders / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D061108:Social Media / Q000706:statistics & numerical data*; D012944:Social Support; D009626:Terminology as Topic; D055815:Young Adult
keywords: Adolescent health; Eating disorders; Pro-eating disorder; Social media; Social networks; Social support; Twitter