title: Group dynamics are associated with weight loss in the behavioral treatment of obesity.
abstract: OBJECTIVE
  To assess whether group dynamics are associated with weight loss, session attendance, and self-monitoring adherence after 6 months of lifestyle intervention for obesity.
  
  
  METHODS
  Women with obesity (N = 125; mean ± SD BMI = 37.84 ± 3.94 kg/m(2) ; age =  51.99 ± 10.81 years) participated in a 24-week group-based lifestyle weight loss intervention and achieved a weight loss of 9.13 ± 7.15 kg after 6 months. Participants reported their perceptions of group conflict, avoidance, engagement, social support, and attraction at the end of treatment. Multiple regression with forward selection assessed which group dynamic variables were associated with weight loss, attendance, and adherence.
  
  
  RESULTS
  Greater perceived group conflict was associated with smaller weight losses (β = 1.833, P = 0.044) and lower attendance (β = -2.313, P = 0.002) and adherence rates (β = -2.261, P = 0.030). Higher group attraction was associated with higher attendance rates (β = 0.051, P = 0.039). The association between perceived conflict and weight change was mediated by attendance and adherence (P = 0.019).
  
  
  CONCLUSIONS
  Findings demonstrate that group dynamics associate with weight loss outcomes, attendance, and adherence. Addressing conflicts and fostering acceptance among group members may promote success in group-based lifestyle interventions for obesity.
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Nackers
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Dubyak
authors.affiliation: Department of Biostatistics, University of Florida, Gainesville, Florida, USA.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Aging and Geriatric Research, University of Florida, Gainesville, Florida, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Anton
authors.affiliation: Division of Preventive Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Gareth R
authors.initials: GR
authors.lastname: Dutton
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Perri
mesh_terms: D000328:Adult; D000368:Aged; D001521:Behavior Therapy; D005260:Female; D006801:Humans; D008019:Life Style; D008875:Middle Aged; D009765:Obesity / Q000628:therapy*; D010349:Patient Compliance; D012944:Social Support; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D015431:Weight Loss; D055815:Young Adult