Motivational Interviewing for Weight Loss
|Study Design:||Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Single (Participant); Primary Purpose: Treatment|
Behavioral: Motivational Interviewing (Treatment Group)
Behavioral: Social Skills Training (Control Group)
|Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations|
|Overweight and obese youth (BMI ≥ 85th %ile for age and gender) were eligible to participate and were recruited directly by the primary investigators from the Toronto East General Hospital's Healthy Lifestyles program, comprised of children and adolescents ages 10-18 years who are seeking diet and exercise treatment for their obesity.|
|Significant events and approaches for the overall study following participant enrollment, but prior to group assignment|
|Individuals were excluded if they: 1) were taking medication whose side effects may influence weight gain or weight loss, 2) did not speak English, 3) had a known developmental delay, and 4) reported being pregnant and/or having an active eating disorder.|
The control group received social skills training in place of motivational interviewing, conducted over 6 months by an interventionist not trained in MI to avoid cross-contamination.
The social skills interventionist used a standardized treatment manual, developed and validated for children and adolescents. The social skills interventionist offered advice (as opposed to eliciting ideas from the client, as is the case with MI) and clients were assigned goals to work on without specific regard for the clients’ readiness to change. Sessions were based around finding appropriate ways to navigate typical social situations (for example, how to negotiate with parents, how to manage emotions or how to make friends).
The Treatment group received Motivational Interviewing (MI). MI is a client-centered, directive method of therapy for enhancing intrinsic motivation to change by exploring and resolving ambivalence (Miller and Rollnick, 2002). MI manifests through specific strategies, such as reflective listening, summarization, shared decision making, and agenda setting.
A clinical psychology doctoral student trained in MI administered the intervention over the course of 6 months to participants assigned to the treatment group. The MI intervention comprised six individual MI treatment sessions, each approximately 30 minutes in length.
Participant Flow: Overall Study
|Control Group||Treatment/Experimental Group|
|Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.|
|No text entered.|
|Treatment Group (Motivational Interviewing)||
The treatment group received Motivational Interviewing (MI), which is a client-centered, directive method of therapy aimed at enhancing a client’s intrinsic motivation to change by exploring and resolving ambivalence.
MI utilizes strategies to guide the patient, as opposed to offering advice or focusing on accomplishing specific goals. For example, using reflective listening and shared decision making are common within the MI approach.
Six individual MI sessions, approximately 30 minutes in length each, were provided by a trained clinical psychology doctoral student.
|Control (Social Skills Training)||
The control group received social skills training in place of Motivational Interviewing (MI). The social skills training was provided by a therapist who was not trained in MI to avoid cross-contamination.
The social skills training provided was a standardized and manualized treatment, developed and validated for children and adolescents. As part of this training, the interventionist offered advice and clients were assigned specific tasks to work on. No consideration of clients’ readiness to change was made in this group.
|Total||Total of all reporting groups|
|Treatment Group (Motivational Interviewing)||Control (Social Skills Training)||Total|
Overall Participants Analyzed
Count of Participants
|<=18 years||20 100.0%||20 100.0%||40 100.0%|
|Between 18 and 65 years||0 0.0%||0 0.0%||0 0.0%|
|>=65 years||0 0.0%||0 0.0%||0 0.0%|
Mean (Standard Deviation)
|14.1 (1.8)||13.7 (1.7)||13.9 (1.7)|
Sex: Female, Male
Count of Participants
|Female||14 70.0%||9 45.0%||23 57.5%|
|Male||6 30.0%||11 55.0%||17 42.5%|
Region of Enrollment
|1. Primary:||Weight Efficacy Life-style Questionnaire [ Time Frame: Baseline, 6 month follow-up ]|
|2. Primary:||Child Dietary Self-Efficacy Scale [ Time Frame: Baseline, 6 month follow-up ]|
|3. Secondary:||Physiological Outcomes: BMI [ Time Frame: Baseline, 6 month follow-up ]|
|4. Secondary:||Physiological Outcomes: Waist Circumference [ Time Frame: Baseline, 6 month follow-up ]|
|5. Secondary:||Psychological Well-being [ Time Frame: Change over time from Baseline to 6 months (measured monthly) with a 12 months reassessment ]|
Limitations and Caveats
|Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data|
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|Principal Investigators are NOT employed by the organization sponsoring the study.|
|There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.|
Results Point of Contact:
Organization: The Hospital for Sick Children
phone: 416. 813 7654 ext 328363
|Responsible Party:||Jill Hamilton, The Hospital for Sick Children|
|ClinicalTrials.gov Identifier:||NCT01246349 History of Changes|
|Other Study ID Numbers:||
|First Submitted:||November 11, 2010|
|First Posted:||November 23, 2010|
|Results First Submitted:||January 17, 2014|
|Results First Posted:||April 21, 2014|
|Last Update Posted:||November 17, 2017|