Peer-enhanced Intervention to Support Teen Weight Loss

Study Overview
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Brief Summary
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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
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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.

Official Title
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Peer-Enhanced Intervention to Support Teen Weight Loss

Conditions
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Obesity

Intervention / Treatment
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* Behavioral: CBT with peer-enhanced activities
* Behavioral: CBT with supervised aerobic exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adolescents 13-16 years old 20-90% overweight with reference gender and age At least 1 parent who can participate English speaking Agree to study participation and random assignment Be available for long-term follow-up Exclusion Criteria: Current involvement in another weight loss program Unable to adhere to prescribed dietary plan and physical activity due to medical condition Unable to understand intervention materials In treatment for or diagnosed with psychiatric disorder

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CBT with peer-enhanced activities<br>Cognitive behavioral treatment (CBT) with peer-enhanced adventure therapy. The peer intervention, ''adventure therapy,'' is based on the principles of Outward Bound and was expected to affect weight status through a positive effect on self-concept. | Behavioral: CBT with peer-enhanced activities<br> <br> |
| Active Comparator: CBT with supervised aerobic exercise<br>Cognitive behavioral treatment (CBT) with supervised aerobic exercise. Activities for the supervised exercise intervention included use of treadmills, stationary bicycles, and other aerobic activities selected by participants, including dance videos and brisk walking within the clinic setting. | Behavioral: CBT with supervised aerobic exercise<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Adolescent Body Mass Index (BMI) |  | 12 and 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self concept | Self- Perception Profile for Adolescents and the Physical Self-Worth Scale | 12 and 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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obesity, adolescent, weight loss, body mass index, evaluation studies, peer group, behavior therapy, diet, exercise, self efficacy, parents