Health Promotion Practice Month XXXX Vol. XX , No. (X) 1–10 DOI:10.1177/1524839919833989 Article reuse guidelines: sagepub.com/journals-permissions © 2019 Society for Public Health Education 1 Background. The health impact of youth mentors serving in the delivery of child nutrition and physical activity (PA) interventions on youth mentors themselves has been understudied. Objective. The primary objective of the cur- rent study was to examine the impact of engaging youth mentors in the delivery of a summertime childhood obe- sity prevention intervention on youth mentors’ behavioral health. Method. Data were collected at baseline and postintervention. A survey of validated nutrition, mental health, PA, and psychosocial questionnaires was admin- istered. Diet was assessed via 24-hour recall. Height, weight, and waist circumference (WC) were measured. In-depth interviews were conducted with youth mentors. Results. Eleven youth mentors enrolled: 60% were female, mean age was 16.1 ± 0.38 years, and 100% were Black. Mean kilocalories (p = .05), sugar-sweetened beverage intake (p = .08), and waist circumference (p = .04) decreased. In-depth interviews were conducted with 11 youth mentors, and three themes emerged: perceived improvement in nutrition, PA, and mental health-related behaviors; formation of a positive role modeling rela- tionship with the child campers; and strengthening of higher education goals and future career aspirations. Conclusions. Youth mentor staffing may be an important intervention strategy for changing health behaviors among youth mentors. Results from this study can be used to inform utilization of youth mentors in the delivery of this and similar health behavior interventions in the future. Keywords: child/adolescent health; obesity; chronic disease; career development/professional preparation > INTRODUCTION Almost a third of U.S. youth are overweight or obese (Skinner, Ravanbakht, Skelton, Perrin, & Armstrong, 2018). Significant differences in the preva- lence of obesity exist between racial or ethnic groups, and the risk increases with age (Hales, Carroll, Fryar, & Ogden, 2017; Ogden, Carroll, Kit, & Flegal, 2014). The harmful consequences of obesity on health and aca- demic achievement, along with the propensity for unhealthy weight status to perpetuate into adulthood, are gravely concerning (Halfon, Larson, & Slusser, 2013; Taras & Potts-Datema, 2005). Thus, now more than ever, there is need to identify effective interven- tion strategies to treat and prevent childhood obesity and the behaviors fueling the problem. It is well-established that use of a theoretical frame- work is critical in the design and implementation of health behavior interventions due to the inherent complexity of behavior (Sharma M, 2011). The social 833989HPP XX X 10.1177/1524839919833989Health Promotion PracticeHopkins et al. / CAMP <sc>nerf</sc> YOUTH MENTOR OUTCOMES research-article 2019 1 The Ohio State University, Columbus, OH, USA 2 The Virginia Polytechnic Institute and State University, Blacksburg, VA, USA Authors’ Note: Clinical Trials No. NCT02908230/09-19-2016. Address correspondence to Carolyn Gunther, Associate Professor, Department of Human Sciences, Ohio State University, 1787 Neil Avenue, 313 Campbell Hall, Columbus, OH 43210, USA; e-mail: gunther.22@osu.edu. Youth Mentor Dietary Outcomes and Waist Circumference Improvement: Camp NERF Study Findings Laura C. Hopkins, PhD, MSPH, RDN, LDN 1 Alison Webster, MS 1,2 Julie A. Kennel, PhD, RD, LD 1 Kelly M. Purtell, PhD 1 Carolyn Gunther, PhD 1