Development and Evaluation of a Web-based Parental Role Modeling Program for Childhood Obesity Management

The goal of this clinical trial is to learn whether an online family health education program can help Vietnamese children aged 7-9 years with overweight or obesity develop healthier habits. The main questions it aims to answer are: 1. Does the program improve parents' confidence, role modeling behaviors, family communication, and healthy family practices? 2. Does the program improve children's eating habits, physical activity, screen time, and body measurements related to overweight and obesity? Researchers will compare the online family health education program with standard health education materials to see whether the program leads to greater improvements in children and their families. Participants will: 1. Complete surveys about their family's health habits and daily routines. 2. Attend health checkups that include measurements of height, weight, and waist size. 3. Receive either the online family health education program or standard health education materials. 4. Complete follow-up assessments after the program and four months later. The results of this study may help identify effective ways to support families in managing childhood overweight and obesity in Vietnam.

Inclusion Criteria: * Parents of children aged 7-9 years with a BMI-for-age z-score ≥ +1 standard deviation (SD) according to the World Health Organization growth reference. * Willingness to participate in a web-based program, including attending online workshops and completing behavioral tasks and assessment. * Availability of the internet and digital devices necessary to engage in the web-based program. * Parents who were responsible for the child's daily health-related routines, including meals, physical activity, and screen-time management. Exclusion Criteria: * Children with chronic medical conditions, physical disabilities, or developmental disorders that significantly affect dietary or physical activity behaviors or growth. * Parents who are unable to commit to the study timeline or program schedule. * Families already participating in another obesity-related program.