Obesity has become epidemic among U.S. children and results in serious negative health consequence over the lifespan. Thus, identifying effective interventions for prevention of obesity in children is paramount The purpose of the proposed study is to design, implement, and evaluate a culturally appropriate, multi-leve trans-community prevention intervention for decreasing obesity risk (measured by BMI percentile) in 3 to 5 year-old rural Hispanic and American Indian children. The primary intervention site will be Head Star centers, where enrolled low-income preschool children spend the majority of their days. The intervention Child Health Initiative for Lifelong Eating and Exercise (CHILE), will include policy changes to addres environmental determinants of healthful eating and physical activity, as well as individual and interpersona level strategies to promote increased moderate to vigorous physical activity;increased consumption of fruits vegetables, and whole grains;decreased consumption of sweetened beverages and high-fat foods;an decreased television viewing/screen time. The intervention includes six components: a classroom curriculu for Head Start classrooms;an in-service training program for Head Start teachers and aides;training fo Head Start food service staff;a home- and Head Start-based program for families;use of local health car providers as community change agents, advisors, and role models;and a community grocery store progra to increase availability and promotion of healthy food options. The study will employ a nested cohort desig in which 16 Head Start centers will be randomly assigned to intervention or control conditions. Two cohort of 3-year-old children within each Head Start center will be followed for two years post-randomization Participants will be assessed using a measurement and interview protocol across four time points. Data wil be analyzed using multi-level modeling to partition variance into individual- and Head Start- or intervention level components, and to explore individuals'change over time and potential mediating effects.