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.