This project will be a natural experiment examining issues related to school wellness policy development and implementation, and changes in school nutrition environments as schools work to comply with the wellness policy mandate. The aims of this project are to describe adequacy of wellness policies submitted by Pennsylvania Local Education Agencies, assess level of policy implementation and changes in school nutrition environments, identify factors related to policy adequacy, policy implementation, and positive school nutrition environment changes, and establish procedures to link study body mass index data to policy data. The study will involve K-12 schools.