The purpose of this study was to develop a children's active health index based on the three main factors-the environment, lifestyle, and the physiological and behavioral traits of children of various ages. To acquire dynamic data, a prospective cohort research was carried out. Construct a dynamic digital health portrait to detect and warn children's health problems early, intervene in a timely manner, and explore a new paradigm of children's active health management.

Under the guidance of the World Health Organization's (WHO) Global Strategy for Women's, Children's, and Adolescents' Health (2016-2030) and China's Child Development Programme (2021-2030), as well as the comprehension that the primary focus of medical care in the future will gradually shift from disease diagnosis and treatment to disease prevention and health management, this study will develop a children's active health index based on the three main factors-the environment, lifestyle, and the physiological and behavioral traits of children of various ages-and conduct a prospective child cohort study. Gather multi-dimensional children cohort data from many sources (medical facilities, schools, families, and communities) that covers physiological indicators, behavioral habits, dietary record, and so on. The meta-model of children's active health is built using ordinary differential equations in conjunction with digital intelligence technology, which enables real-time and all-around data collection, establishes dynamic digital health portraits for children, and dynamically monitors the health status of children as it varies over time and in response to environmental changes. The ultimate goal of this approach is to identify and warn children's health problems early on, implement timely intervention, and ultimately investigate a new paradigm of children's active health management.

Inclusion Criteria:

• Age≤ 18 years old, regardless of gender.
• Subject and/or guardian agrees to participate in this trial and signs the informed consent form.

Exclusion Criteria:

• The investigator judged that the subject had poor compliance and was unable to complete the study as required.
• Inability to understand the investigator's presentation or description of this trial.
• Other conditions judged by the investigator to be unsuitable for participating in the trial, such as: acute trauma, critical condition, restlessness of the subject, etc.

The target study participants were children aged 0-18 years.