Objective To evaluate a 12-session home and community-based health promotion/obesity prevention program (Challenge!) on changes in BMI, body composition, physical activity (PA), and diet. Methods 235 African-American adolescents (11–16 yrs, 38% overweight/obese) were recruited from low-income urban communities. Baseline measures included weight, height, body composition (dual-energy x-ray absorptiometry (DEXA) and bioelectrical impedance), physical activity (PA) (accelerometry), and diet (food frequency). PA was measured by time in play-equivalent physical activity (PEPA≥1800 activity counts/min). Participants were randomized into a home- and community-based health promotion/obesity prevention controlled trial, anchored in social cognitive theory and involving motivational interviewing techniques, and delivered by college-enrolled, African-American mentors. Control adolescents did not receive the intervention or a mentor. Post-intervention (10 mos) and delayed follow-up (24 mos) evaluations were conducted. Longitudinal analyses using random mixed effects models and generalized estimating equations (GEE) examined direct and moderated effects of time, gender, and baseline BMI category on changes at both follow-ups. Results Retention was 76% (178/235) over 2 years; overweight/obese status declined 5.3% among intervention adolescents and increased 11.3% among control adolescents (χ2=5.8, p=0.02, GEE). Among males, but not females, fat free mass was significantly higher among intervention members at both follow-up evaluations. PA effects were moderated by baseline BMI category; among adolescents ≥ 85th percentile, control adolescents averaged 25.5 min less daily activity than intervention adolescents (p=0.018) at the 10-mo, but not the 24-mo follow-up. Intervention adolescents declined significantly more in snack and dessert consumption than control adolescents (p=0.045). Conclusion A 12-session, home-and community-based intervention, based on social cognitive theory and delivered by college-enrolled mentors, had sustained effects over 24 months in preventing an increase in BMI category, in enhancing fat free mass among males, and in reducing snack and dessert intake. The intervention prevented PA declines among the heaviest adolescents, but effects were not sustained.

Multilevel interventions can be uniquely effective at addressing minority health and health disparities, but they pose substantial methodological, data analytic, and assessment challenges that must be considered when designing and applying interventions and assessment. To facilitate the adoption of multilevel interventions to reduce health disparities, we outline areas of need in filling existing operational challenges to the design and assessment of multilevel interventions. We discuss areas of development that address overarching constructs inherent in multilevel interventions, with a particular focus on their application to minority health and health disparities. Our approach will prove useful to researchers, as it allows them to integrate information related to health disparities research into the framework of broader constructs with which they are familiar. We urge researchers to prioritize building transdisciplinary teams and the skills needed to overcome the challenges in designing and assessing multilevel interventions, as even small contributions can accelerate progress toward improving minority health and reducing health disparities. To make substantial progress, however, a concerted and strategic effort, including work to advance analytic techniques and measures, is needed.