Childhood obesity is a national epidemic that disproportionately burdens low income and ethnic minority populations. By preschool, nearly one-third of low income children are already overweight or obese, setting the stage for adverse health outcomes over their life course. Evidence is mounting that individual-focused, single-component interventions fail to produce long-term population-level changes in obesity-related outcomes. Evidence increasingly supports creating entire environments (e.g., schools) in which the healthy choice is the default option. The investigators will conduct a pragmatic cluster randomized trial to evaluate the effectiveness of a multilevel (organization, teacher, parent, child) intervention to support healthy eating and physical activity in preschools. The study is being conducted in partnership with Child Care Resource Center (CCRC), a non-profit organization dedicated to ensuring that all children receive high quality preschool experiences. The investigators will randomly assign 60 preschool sites (stratified by size), located in underserved areas of Los Angeles, to the intervention or a usual practice control conditions. The investigators will evaluate the effectiveness of the intervention on child BMI z-scores (primary outcome) and parent-reported child nutrition and physical activity (secondary outcomes). The investigators will systematically examine the implementation process to understand factors that may facilitate or hinder intervention uptake and success. The findings from this work will be critical for informing future dissemination efforts.