title: A systematic review of the effectiveness of group versus individual treatments for adult obesity.
abstract: BACKGROUND
  Both group and individual modes of delivery are employed for obesity treatments. Commercial weight loss groups commonly employ group-based delivery, while many clinical based settings employ one-to-one delivery. We systematically reviewed randomised controlled trials of treatments for adult obesity to compare the effectiveness of group-based to individual-based modes of treatment delivery.
  
  
  METHODS
  We searched 7 electronic databases and 2 journals and reviewed secondary references, based on a priori criteria to systematically review: randomised controlled trials of obesity treatments, participants with BMI >or=28 kg/m(2), age >or=18 years, comparison groups including at least 1 group-based and 1 individual-based treatment group, and follow-up >or=1 year. We extracted data and conducted meta-analysis of weight change.
  
  
  RESULTS
  Eleven comparison groups from 5 qualifying trials were obtained, representing a total participant pool of 336. Significantly greater (p = 0.03) weight change at 12 months was found in group-based over individualbased treatment, and sub-analyses showed that increased effectiveness was associated with the use of financial reward and psychologist-led interventions.
  
  
  CONCLUSIONS
  Group-based interventions were more effective than individual-based interventions among a predominantly female participant pool receiving psychologist-led interventions. Future studies to explore differences by professional group and interventions among men, which are accompanied by economic evaluation, are recommended.
authors.affiliation: Health Services Research Unit, School of Medicine, University of Aberdeen, UK. v.a.paul-ebhohimhen@abdn.ac.uk
authors.forename: Virginia
authors.initials: V
authors.lastname: Paul-Ebhohimhen
authors.forename: Alison
authors.initials: A
authors.lastname: Avenell
mesh_terms: D000328:Adult; D000368:Aged; D001521:Behavior Therapy / Q000379:methods; D015992:Body Mass Index; D004032:Diet; D004046:Dietetics; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D012944:Social Support; D016896:Treatment Outcome; D015431:Weight Loss