Abstract
CONTEXT: Successful treatment approaches are needed for obesity in adolescents. Motivational interviewing (MI), a counseling approach designed to enhance behavior change, shows promise in promoting healthy lifestyle changes. OBJECTIVE: Conduct a systematic review of MI for treating overweight and obesity in adolescents and meta-analysis of its effects on anthropometric and cardiometabolic outcomes. DATA SOURCES: We searched Medline, Embase, Cumulative Index to Nursing and Allied Health Literature, PsychINFO, Web of Science, Cochrane Library, and Google Scholar from January 1997 to April 2018. STUDY SELECTION: Four authors reviewed titles, abstracts, and full-text articles. DATA EXTRACTION: Two authors abstracted data and assessed risk of bias and quality of evidence. RESULTS: Seventeen studies met inclusion criteria; 11 were included in the meta-analysis. There were nonsignificant effects on reducing BMI (mean difference [MD] -0.27; 95% confidence interval -0.98 to 0.44) and BMI percentile (MD -1.07; confidence interval -3.63 to 1.48) and no discernable effects on BMI z score, waist circumference, glucose, triglycerides, cholesterol, or fasting insulin. Optimal information size necessary for detecting statistically significant MDs was not met for any outcome. Qualitative synthesis suggests MI may improve health-related behaviors, especially when added to complementary interventions. LIMITATIONS: Small sample sizes, overall moderate risk of bias, and short follow-up periods. CONCLUSIONS: MI alone does not seem effective for treating overweight and obesity in adolescents, but sample size and study dose, delivery, and duration issues complicate interpretation of the results. Larger, longer duration studies may be needed to properly assess MI for weight management in adolescents.