Participants receive a structured nutrition health education intervention delivered through community-based and school-based models. The program includes four monthly educational sessions using presentations and videos, supported by interactive posters, nutrition leaflets, and dietary and physical activity diaries. The intervention is implemented over four months, followed by a two-month maintenance phase with reinforcement activities involving community health workers, school staff, and family engagement.

Participants do not receive the structured nutrition education intervention. They continue to receive routine health and nutrition education activities available at local community health centers and schools without additional intervention from the study.

A multi-component nutrition health education program delivered through community-based and school-based models. For children aged 5-10 years, both children and their caregivers participate in nutrition education sessions at local health stations. For children aged 11-16 years, the intervention is delivered at ethnic minority boarding schools. The program consists of four monthly structured sessions using presentations and videos, supported by interactive posters, nutrition leaflets, and dietary and physical activity diaries. The key topics include: (1) nutrients and health, (2) prevention of undernutrition and overweight/obesity, (3) healthy dietary habits, and (4) physical activity promotion. The intervention lasts four months, followed by a two-month maintenance phase with reinforcement by community health workers, school staff, and family engagement.

Weight and height will be combined to report BMI in kilogram/meters^2. BMI-for-age z-score calculated according to the 2007 WHO growth standards.

Proportion of participants with abnormal nutritional status, including undernutrition (stunting, underweight, or thinness) and overweight/obesity, classified according to WHO growth reference standards based on age- and sex-specific z-scores.

Nutrition knowledge, attitudes, and practices assessed using a structured questionnaire developed based on the Food and Agriculture Organization of the United Nations Guidelines for assessing nutrition-related knowledge, attitudes and practices.

Knowledge scores ranged from 0 to 11, attitude scores from 0 to 17, and practice scores from 0 to 8, with higher scores indicating better nutrition knowledge, more favorable nutrition attitudes, and better nutrition practices.