Study Design
This study employs an exploratory sequential mixed methods design, as outlined by Creswell & Clark [13]. The approach combines qualitative and quantitative research methodologies, beginning with an exploratory needs assessment using a cognitive social theory framework. The study unfolds in three phases: a qualitative exploration of needs assessment, a three-month trial implementing the Health Promoting School model, and a six-month quantitative Multi-center Cluster Randomised Controlled Trial to evaluate the effectiveness of school-based interventions. The research aims to address three primary questions: 1) What is the effectiveness of school-based physical activity in reducing overweight and obesity in children aged 9-12 years? 2) How do school-based interventions combined with health promoting school programmes contribute to reducing overweight and obesity in children aged 9-12 years? 3) What is the comparative effectiveness of piloting a health promoting school model with nutrition education and physical activity in reducing overweight and obesity in children aged 9-12 years?
Recruitment of School Participant and Setting
The recruitment process began with a preliminary study in several schools in South Sulawesi, focusing on institutions meeting specific criteria such as A and B accreditation. School principals and health practitioners were contacted, and the study's objectives were explained, emphasizing the goal of reducing childhood obesity and its long-term health implications. It was stressed that the study aimed to implement school health promotion without burdening staff with additional work. Upon agreement, parents were invited to learn about the study's purpose and benefits for their children. Parents were offered weekly health education sessions on obesity, its causes, and prevention measures throughout the study. Upon agreement, all schools and parents signed informed consent forms. From an initial pool of 15 identified schools, cluster randomization was used to select eight schools from three districts with varying economic levels that met the study criteria.
Sampling Inclusion/Exclusion Criteria
Inclusion criteria for schools encompassed: 1) non-boarding school status; 2) obesity prevalence above 10% based on routine physical examination records; 3) provision of school lunch to over 50% of students. Individual participant inclusion criteria included: a) male and female gender; b) children aged 9-12 years at the time of initial data collection; c) children who are overweight or obese; d) children willing to participate as respondents, complete the intervention, and provide informed consent; e) full-day school attendance. Exclusion criteria included: a) children with clinical conditions or health disorders such as heart disease; b) children absent during the pretest; c) children who left or moved schools; d) children who did not complete the intervention.
Intervention
The intervention comprised three components implemented over a 6-month period: nutrition education, physical activity, and a Health Promoting School model. These interventions were designed to reduce childhood overweight and obesity through education, improved health literacy, and implementation of government-designated healthy school curricula. The description related to the intervention outlined in Table 1.
Nutritional education intervention
This component involved developing a nutrition handbook module through piloting the health promoting school model. The content combined the government's "healthy school" program and WHO cartoon pamphlets, distributed to each school/student in the intervention schools. Nutrition and health education was provided six times for students, twice for parents, and four times for teachers and UKS officers. Topics included the proportion of three healthy meals, choosing drinks and snacks, reducing consumption of Western ready meals, and promoting local food. Nutrition professionals first gave talks to teachers and parents, after which trained teachers were responsible for teaching students. Each talk lasted a minimum of 40 minutes. "My Plate Diet" posters were displayed in all participating classrooms, and a handbook of balanced nutrition modules was distributed to all participants in the nutrition education groups.
Physical Activity Intervention
The "Happy in School Children" program was implemented as the physical activity intervention. This school-based program, originally developed and promoted in urban Beijing since 2004 [14], was adapted for Indonesian school children. The intervention aimed to increase physical activity by offering three 10-minute segments of moderate-intensity physical activity daily. Activities included games, dance, rhythmic gymnastics, and customized exercises, designed to encourage enjoyable forms of physical activity and improve overall fitness levels among participants.
Health Promoting Shool (HPS) Model Trials
Based on WHO guidelines, this model covered six key areas adapted to local needs: 1) healthy school policies, 2) school physical environment, 3) school social environment, 4) community links, 5) action competencies for healthy living, and 6) school health services. The model focused on creating a healthy environment, promoting behavior change, and improving health services through the implementation and strengthening of school health efforts. This comprehensive approach aimed to create a supportive environment for healthy behaviors and reinforce the messages delivered through the nutrition education and physical activity interventions [15].
Table 1. Overview of participant, intervention, measure description, and time frame
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Participant
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Intervention/Treatment
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Measure Description
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Time Frame
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Children School
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Nutrition education
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- Process and learning methods through training and seminars involving class teachers, sports teachers, and distribution of posters in each class.
- Nutrition education is provided twice a week in the classroom through video screenings and posters on the introduction and causes of overweight and obesity status, from the consumption of junk food, foods and drinks high in sugar
- Measuring tools: 1) Chek list; 2) FFQ Measuring scale: ratio and categorical measuring results: conducted trials with the team. Health literacy, the ability of children, orangutans and schools to apply and use information, health promoting school approach measurement tool, in-depth interview and questionnaire distribution.
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3 months trial, 3 months implementation of health promoting school (HPS) model
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|
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Physical Activity
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“A school-based physical activity programme for students called "Happy in school children" was used in the physical activity intervention. The Happy programme was developed as a school-based intervention to promote physical activity in primary school children. The Happy programme, which has been implemented and promoted in urban Beijing since 2004, will be piloted with school children in Indonesia. As a strategy to increase physical activity. To be offered 3 times during the school day, Happy in school children will be organised by professional instructors and teachers to perform 10-minute segments of moderate-intensity, physical activity. Other forms of physical activity include games, dance or rhythmic gymnastics, such as jumping rope, and squatting, or as customised by the curriculum. The 10-minute session consists of four parts: 1) the teacher or students choose cards to determine the activity; 2) some children are chosen to model the exercise in front of the class and other students follow suit (one to three activities are performed at each session); 3) a cool-down period is conducted after the activity; and 4) students are taught health messages. The average energy expenditure for 10 minutes of physical exercise ranges from 25.0-35.1 kcal.33, the goal being that students are encouraged to develop different forms of physical exercise that they enjoy.”
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6 months
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Health Promoting Shool (HPS) Model Trials
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“WHO has developed a set of guidelines covering six areas to be adopted by member states, each country will need to develop detailed indicators and evaluation frameworks to meet their local needs. Indicators and guidelines should be selected based on evidence and theory, with multiple objectives that are relevant, adaptable and achievable, to develop good practice. Indicators and guidelines for selection are based on the following criteria: (1) should be theory-based and evidence-based - based on the concept of HPS and consistent with the values and objectives of the government programme "Healthy Schools"; (2) with broad objectives - to cover all dimensions of HPS and healthy schools; (3) useful and helpful to develop health literacy providing useful and relevant information to assist in school strengthening, and to identify good practices and actions for improvement; (4) relevant and achievable applicable in the local school context; and (5) flexible and adaptable. The healthy school evaluation framework has taken these criteria into consideration. For each of the six key areas, a number of components and checkpoints have been developed to reflect the key elements of a Healthy School, with targets for schools to achieve. Points are awarded if the checkpoint criteria are met. An overall score and scores under each key area can then be calculated. Following the development of the indicators, a series of questionnaires were designed as an assessment tool for schools to evaluate HPS based on the piloted indicators. To ensure the validity and applicability of the newly developed content, it was trialled in schools, through questionnaires. The process of developing content for healthy schools will be in the process of piloting the HPS.”
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6 months
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Parents children (mediators based on SCT)
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- Parental self-efficacy
- Parental behavioural
capability
- Parental outcome expectations and expectancies
- Parental role modelling observational learning Parent’s motivation
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“Healthy environment for healthy foods and physical activity monitoring of behaviours role modeling
Involvement encouragement in healthy
behaviours restriction of unhealthy foods and sedentary behaviours.”
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6 monhts
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School principle, sport teacher, and school canteen keeper
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- Training
- Modelled lesson
- Program into the school curriculum
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“School canteen keeper bers from the cooperation center for five days. Teachers, usually classroom tutors and/or health educators had attended a two-days training session conducted by the staff of their center with the training slides and videos provided by Chinese CDC. They had learned how to inte- grate the program into the school curriculum, and how to perform the activities. Slides and videos about nutrition, childhood obesity, risk factors, health consequences, and prevention were prepared by Chinese CDC and provided to school teachers. Teachers modelled the lessons to ensure that they understood the recommended tech- niques and strategies for implementation.”
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6 monhts
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Assessment of Intervention Effects
Anthropometric measurements were taken at baseline (October-November 2024) and post-intervention (May-June 2025). These included height (measured to the nearest 1 mm using a stadiometer), weight (measured to the nearest 0.1 kg using a calibrated electronic scale), BMI and BMI-z scores (calculated using the World Health Organisation growth reference), and waist circumference (measured to the nearest 0.1 cm using a non-elastic tape). All measurements followed standardized procedures to ensure accuracy and reliability. The comprehensive data collection allowed for a thorough evaluation of the interventions' effectiveness in reducing overweight and obesity among the participating children. The outcome measure description outlined in Table 2.
Table 2. Overview of outcome measure, measure description, and time frame
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Outcome Measure
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Measure Description
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Time Frame
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BMI Z-score
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Where weight will be measured using a body composition meter (Seca 804) to 0.1 kg, and height measured with a stadiometer to 0.1 cm. BMI (kg/m2) will be converted to the Weight and height measurements will be taken twice to obtain accuracy and correct averages. Body mass index (BMI) for age Z score, according in 2007 WHO Growth Standards for children, will be used to classify the risk of being overweight with a Z SD score of 1, overweight with a Z SD score 1, and overweight: BMI Z-score ≤ 3, obesity BMI Z- score ≥ 3.
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6 months intervention combining health promoting school
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Children knowledge
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Children knowledge, the ability to give appropriate answers to questions about nutrition, physical activity, causes of overweight and obesity and how to prevent them. The measuring instrument uses a questionnaire, a ratio measuring scale, the measurement result is determined from the total score set, the correct answer score is given 1) if it is wrong 0)
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6 months intervention combining health promoting school
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Self-efficacy
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Self-efficacy, a person belief in their ability to perform a behaviour, the behaviour is obesity prevention, measured using a 3-point Likert scale, namely 1) agree, 2) disagree, and 3) disagree. Answer score for favourable questions: Agree: 3) Undecided: 2) Disagree:1) Unfavourable question answer score: Agree: 1) Undecided: 2) Disagree: 3)
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6 months intervention combining health promoting school
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Health Literacy
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Health literacy, the ability of children, orangutans and schools to apply and use information, health promoting school approach measurement tool, in-depth interview and questionnaire distribution.
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6 months intervention combining health promoting school
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Study phase
This study will be conducted in three phases as illustrated in Figure 2, encompassing pre-intervention, intervention, and post-intervention stages. A detailed explanation of each phase follows.
Phase I - Pre-Intervention
This phase focuses on assessing the current state of health promotion in schools across three districts (Makassar, Gowa, and Maros). It involves evaluating children's knowledge about nutrition and exercise, their diet and physical activity patterns, and their attitudes, cultural beliefs, visions, and ideas about obesity. Additionally, we will determine the extent to which health promotion related to nutrition and physical activity has been implemented in schools. The phase also includes identifying facilitators and barriers to health promotion in schools within these districts, according to key stakeholders such as the Primary Education Office, Health Office, Youth and Sports Office, Health Promotion Coordinator, District Nutrition Coordinator, and School Health Teams.
Phase II - Intervention
The intervention phase, estimated to last 6 months, is conceptualized using Bandura's social cognitive theory (SCT) approach. School-based interventions will be designed to improve health literacy, reduce BMI, enhance knowledge, and increase self-efficacy, aiming to reduce overweight and obesity in schools. Key components include capacity building for teachers, canteen workers, and school principals; implementation of health promoting schools; development of a pilot model for school-based capacity building; and capacity building for parents to facilitate children's knowledge adaptation. The intervention is based on SCT's three main constructs influencing health behavior change: self-efficacy, goals or intentions, and outcome expectations, with a primary focus on self-efficacy and outcome expectancy constructs.
Phase III - Post-Intervention
This phase will determine the effectiveness of the school-based intervention by measuring changes in BMI, knowledge, self-efficacy, and health literacy. Additional activities include pilot testing of the health promoting school model on children, parents, and teachers; collection of mothers' and teachers' perceptions on model implementation; exploration of respondents' perceptions of the intervention's influence on reducing overweight and obesity; and pilot inspection of the health promoting school model to ensure improved health literacy. Throughout all phases, researchers will conduct random site visits to monitor data collection and intervention implementation, with feedback shared with the field team to ensure adherence to protocols.
Planned Statistic Analysis
Sampel size
The sample size will be determined using the hypothesis test formula for the difference in means between the overweight/obese group and the intervention group with normal weight, as per Lemeshow et al. [16].
Quantitative Statistics
Data will be presented as mean (SD), median, range, or percentage for categorical variables. Statistical analyses will be performed using SPSS, including normality tests, ANOVA, independent t-tests, paired t-tests or Mann-Whitney tests, repeated ANOVA, and ANCOVA. Effect size will be measured using Cohen's D.
Qualitative Analysis
Thematic analysis of focus group transcripts will be conducted independently by two researchers, following a six-step approach: data familiarization, initial coding, theme search, thematic map creation, theme definition and naming, and final analysis. This qualitative data will contextualize results and investigate participants' perceptions and attitudes towards the intervention.