title: Social networks and social norms are associated with obesity treatment outcomes.
abstract: OBJECTIVE
  To examine whether overweight social network members and normative influence for obesity are associated with weight loss outcomes during obesity treatment.
  
  
  METHODS
  Participants (N = 214) in a behavioral weight loss trial reported (a) the weight status of various members of their social network and (b) the level of obesogenic normative influence within their social network. Weight was objectively assessed before and after treatment.
  
  
  RESULTS
  At baseline, participants with partners and best friends who were overweight and those with more children and relatives who were overweight had higher BMIs (P's < 0.03). However, social norms for obesity were not associated with baseline BMI. During treatment, participants lost an average of 4.4% of initial body weight, and social influence factors were adversely associated with weight loss outcomes. Having more casual friends who were overweight at baseline and being part of a social network with stronger social norms for unhealthy eating predicted poorer weight losses (P's < 0.023). Remaining social influence factors and changes in social influence were not associated with treatment outcomes.
  
  
  CONCLUSIONS
  Whereas weight status may "cluster" in social networks, only weight status of casual friends and normative influence for unhealthy eating were associated with obesity treatment outcomes.
authors.affiliation: Department of Allied Health Sciences, University of Connecticut, Connecticut, Storrs, USA.
authors.forename: Tricia M
authors.initials: TM
authors.lastname: Leahey
authors.affiliation: Weight Control and Diabetes Research Center, The Miriam Hospital, Providence, Rhode Island, USA.
authors.forename: Caroline Y
authors.initials: CY
authors.lastname: Doyle
authors.affiliation: Department of Psychology, Idaho State University, Pocatello, Idaho, USA.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Allied Health Sciences, University of Connecticut, Connecticut, Storrs, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Bihuniak
authors.affiliation: Weight Control and Diabetes Research Center, The Miriam Hospital, Providence, Rhode Island, USA.
authors.forename: Rena R
authors.initials: RR
authors.lastname: Wing
mesh_terms: D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000523:psychology / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic; D066262:Social Norms; D012944:Social Support; D016896:Treatment Outcome; D015431:Weight Loss