This study will evaluate iPOP-UP, a newly-optimized intervention to improve adherence to national guidelines for the management of childhood obesity, among 84 primary care practices affiliated with three health systems serving children with racial and ethnic, socio-economic, rural-urban, and geographic diversity.

This multi-site, parallel 2-arm cluster randomized controlled "Hybrid Type 2" effectiveness-implementation trial will use mixed methods (electronic health record (EHR) data analysis, surveys, interviews, and focus groups) to simultaneously evaluate (1) the effectiveness of the iPOP-UP implementation package in improving clinical care and children's BMI outcomes in pediatric primary care setting and (2) the impact of the implementation strategy on the reach, adoption, fidelity, cost, and maintenance of the intervention.

The unit of randomization in this study is pediatric primary care practices. Within the participating 84 practices, pediatric primary care clinicians working at the implementation sites will be invited to participate in pre- and post-intervention surveys assessing their practice behaviors, obesity-related attitudes, beliefs, and self-efficacy, EHR usage and attitudes, and training preferences. In addition, a limited data set of EHR from patients visits will be queried and analyzed to evaluate clinical care outcomes and children's BMI outcomes. Limited data (to include dates and geographic information but no facial identifiers) will be queried and analyzed for all children 1) age 2.0 to ≤18 years-old at baseline, 2) with a well-child visit, during which height and weight are measured, at one of the participating practices during the study period, and 3) with a BMI ≥85th percentile for age/sex (CDC criteria for overweight/obesity).