StEP OUT - This Mentored Patient-Oriented Research Career Development Award (K23) proposal will address an urgent need to advance the science of child obesity prevention in some communities, a priority of the National Heart, Lung, and Blood Institute. Simultaneously, it will prepare the applicant, Michelle Katzow, MD, MS, to become an independent investigator specializing in interventions that begin in pregnancy to prevent child obesity using innovative and scalable delivery platforms. Risk factors for lifelong cardiometabolic morbidity and mortality related to obesity are identifiable in pregnancy and early infancy. Few interventions have improved child obesity related outcomes at this lifestage. The Starting Early Program (StEP) was designed to fill this gap. The program delivers nutrition and parenting support sessions in the primary care setting and has significant positive impacts on child obesity-related outcomes. These impacts are dose dependent, such that families who attend more sessions have significantly better outcomes than families who attend fewer sessions. Many families cite geographic distance as a problem that decreases program engagement. Though the original program was delivered in person, a second cohort receiving the program in 2020 experienced a rapid conversion to remote, videoconference delivery due to the global pandemic. Despite many challenges posed by the pandemic, attendance among participants in this ongoing cohort has been higher than among participants in the original, in-person cohort. In addition to improving attendance, remote delivery has created opportunities for more frequent sessions than would be typical in contexts outside of primary care that are otherwise well-suited for obesity prevention programs, such as the Special Supplemental Nutrition Program for Women, Infants, & Children (WIC). WIC reaches more than half of all infants in the nation and has a high concentration of children at risk of obesity. However, no studies have examined videoconference-based, longitudinal interventions for child obesity prevention in WIC. This K23 proposes to develop and test Starting Early to Prevent Obesity Using Telehealth (StEP OUT), an adapted version of StEP optimized for remote, virtual delivery through WIC. Aim 1 will identify knowledge and attitudes of key stakeholders likely to impact engagement and outcomes of StEP OUT; Aim 2 will iteratively adapt and test StEP OUT in sequential small cohorts; and Aim 3 will conduct a pilot randomized controlled trial (RCT) to evaluate acceptability and feasibility of StEP OUT. In the process, the candidate will obtain essential career development skills in four domains: 1) qualitative methods; 2) CBPR; 3) iterative intervention adaptation; and 4) conduct of clinical trials. The resources of Northwell Health and an expert team of interdisciplinary mentors and advisors will provide an outstanding context to launch Dr. Katzow’s career. This project will provide the necessary data for Dr. Katzow’s future R01 submission of a large-scale RCT testing the efficacy of StEP OUT.