PROJECT SUMMARY/ABSTRACT The Mentored Research Scientist Development Award (K01) will support my long-term career goal of testing whether the mental and physical health of youth, particularly those from historically marginalized groups, improves when social norms encourage widespread promotion of body positive messages. Stigma in its many forms has been identified as a fundamental cause of health problems, but weight stigma has received relatively less attention than other types of stigma. For larger bodied people, weight stigma is associated with depression, anxiety, substance use, low self- esteem, and poor body image, increased social isolation, adverse academic outcomes, disordered eating, reduced physical activity, and increased overweight/obesity. High rates of adolescent obesity disproportionately impact Latinx youth in the U.S. putting them at increased risk for poor health outcomes. Social media offers untapped potential to promote healthy norms around body size and shape. To leverage youth’s heavy engagement with social media and its ability to shape norms, I am proposing a social media intervention designed to positively influence adolescents’ views of those living in larger bodies, increase the likelihood that adolescents promote positive content about body size and shape, and discourage adolescents from engaging in harmful actions towards others because of their weight. The limited research on social media interventions to promote body positivity (positive feelings about body size and shape) has involved a one-time intervention exposure and has largely been done with White, female adult samples. My proposed research will address these gaps by studying Latinx youth of all genders who will receive multiple exposures to body positive messages via Instagram. The specific aims of this proposal are to (1) use qualitative methods to understand Latinx youth’s view on body positive messages to inform the development of an Instagram body positivity campaign, (2) develop an Instagram body positivity campaign to increase body positivity among Latinx adolescents, and (3) conduct a pilot RCT to assess the impact of a body positivity Instagram campaign tailored to Latinx youth on weight stigma and mental health. For Aim 1, I will conduct 20 interviews with youth about body positivity to identify key themes that will inform development of a campaign to promote body positivity among Latinx youth. In Aim 2, I will develop 20 campaign messages and pre-test those messages with 100 Latinx adolescents to select messages for use in the pilot RTC. In Aim 3, 114 Latinx adolescents will engage with a study campaign (intervention or control) for 4 weeks and complete baseline and follow-up surveys. My training goals will support my research efforts including the development of expertise in (1) weight stigma and evidence-based strategies to promote body positivity, (2) applying principles of community-engaged participatory research to develop culturally relevant interventions, (3) developing health communication interventions using social media, and (4) designing and analyzing longitudinal randomized-controlled trials. My training will be enhanced with professional development opportunities, institutional resources, and exceptional mentorship. This K01 will allow me to establish an independent research program aimed at diminishing the toll of weight stigma.

PROJECT NARRATIVE Body positivity, the promotion and acceptance of diverse body sizes and appearances, is one approach to mitigating weight stigma, which is associated with depression, anxiety, disordered eating, reduced physical activity, and weight gain. Latinx adolescents have higher rates obesity than their white counterparts and are at risk of experiencing multiple forms of stigmatization. This study will assess the impact of a social media campaign that promotes body positivity on weight stigma and mental health among Latinx youth, compared to a control campaign.