Cities for Better Health Childhood Obesity Prevention Initiative in JAPAN

Inclusion Criteria: * Children aged 6 to 12 years who are currently enrolled in one of the public elementary schools located within the 22 participating Junior High School District clusters in Chiba City. * The parent or legal guardian of each child must provide written informed consent prior to participation. * Parents or legal guardians must have sufficient Japanese language proficiency to understand study procedures, complete questionnaires, and provide accurate information during the study. * Children must be physically and cognitively capable of participating in school- and community-based activities involved in the intervention. * Participants must not have any medical conditions that would preclude safe participation in routine physical activities promoted by the intervention. Exclusion Criteria: * Children whose parents or legal guardians fail to provide complete informed consent. * Families who withdraw consent at any point during the study period. * Children who independently express refusal to participate, even with parental consent. * Children with serious physical, psychological, or developmental disorders that prevent them from participating safely in the program's activities. * Families planning to relocate outside of Chiba City during the study period, making follow-up assessment infeasible.