Peer-enhanced Intervention to Support Teen Weight Loss
Condition: Obesity
MeSH terms: Weight Loss
Study type: Interventional

Summary: 
      The purpose of this study is to determine whether adding a peer-based intervention based on
      an outward bound model is more effective than a standard behavioral weight intervention for
      helping adolescents lose weight.
    

Detailed description: 
      The prevalence of overweight in children and adolescents has increased significantly during
      the last two decades. While there are empirically supported weight management interventions
      for school age children, treatment findings with overweight adolescents are not as
      consistent. A potential limitation of weight control interventions for adolescents is the
      minimal attention given to the peer group as an active component of treatment. We have
      promising findings from a pilot study that involves adding an innovative peer-based
      intervention (peer-based skills training; PBST) to cognitive- behavioral weight management
      treatment for adolescents. The purpose of the proposed study is to expand the pilot by: 1)
      increasing our sample size, 2) assessing weight loss over a longer time period, and 3)
      evaluating the role of psychosocial variables, as well as physical activity and diet, in
      mediating treatment outcome. It is hypothesized that overweight adolescents randomized to
      cognitive-behavioral treatment with peer enhancement will demonstrate greater weight loss at
      long term follow-up than adolescents randomized to cognitive-behavioral treatment with
      exercise.

      One hundred and fifty adolescents between the ages of 13 and 16 years and 20% and 90%
      overweight will be randomized to one of two treatment conditions: 1) Cognitive-Behavioral
      Weight Loss Treatment with Peer-Based Skills Training (CBT+PBST) or 2) Cognitive-Behavioral
      Weight Loss Treatment with Exercise (CBT+EXER). Measures of height, weight, physical
      activity, diet, and psychosocial functioning will be obtained at baseline, end of treatment,
      12 months, and 24 months after randomization. A between-groups t-test will be conducted to
      evaluate group differences in change in percent overweight between baseline and 24-month
      follow-up. Hierarchical linear modeling will be used to assess the pattern of weight loss for
      the two treatment groups across four time points: baseline, end of treatment, 12 month, and
      24 month follow-up. Effects of treatment on psychosocial measures will be analyzed using
      mixed analysis of variance with treatment condition as the between subjects factor and a
      within subject factor of time. Finally, a series of regression analyses will be conducted to
      evaluate the role of psychosocial variables, physical activity, and diet, as mediators of
      treatment outcome.
    

Intervention name(s): CBT with peer-enhanced activities; CBT with supervised aerobic exercise
Intervention type(s): Behavioral; Behavioral
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: obesity; adolescent; weight loss; body mass index; evaluation studies; peer group; behavior therapy; diet; exercise; self efficacy; parents