BACKGROUND: Adolescents are not meeting current recommendations for daily physical activity, nutrition, and screentime which has been associated with overweight and obesity. Understanding the mediators that facilitate teens in improving their healthy lifestyle behaviors may be helpful in halting this crisis. PURPOSE: The purpose of this systematic review was to assess published findings regarding mediators of adolescent energy balance behaviors. METHOD: We followed the Institute of Medicine guidelines for completing a systematic review. DISCUSSION: Fourteen analyses from 12 studies were included with mediating variables tested for nutrition, physical activity, and screen time. Mediators were identified for all three behaviors and were primarily on the individual level of the social ecological model. CONCLUSIONS: Combining findings from this and other reviews of mediators can help guide researchers in choosing mediating factors for specific target behaviors.