A school-based, multi-faceted health promotion programme to prevent obesity among children: protocol of a cluster-randomised controlled trial (the DECIDE-Children study)

Introduction Obesity is a public health concern that is becoming increasingly more serious worldwide. Effective and sustainable childhood obesity prevention strategies may help to reduce the prevalence of obesity and may have an impact on lifelong health. However, few such strategies have been rigorously evaluated for Chinese children in different regions of China. Methods and analysis The Diet, ExerClse and CarDiovascular hEalth-Children is a cluster-randomised controlled trial that aims to assess the effectiveness and sustainability of a school-based, multi-faceted intervention to prevent obesity among Grade 4 primary school students (8-10 years old) in China. Twenty-four schools (approximately 1200 students) from above average, average and below average developed regions in China will be randomised to an intervention (12 schools) or usual practice (12 schools) group. The intervention will last for one school year (9 months) and consists of activities towards students, parents and school environment. A smartphone application will be used to assist in providing information on, monitoring and providing feedback on the behaviours and body weight of the students. Data will be collected at baseline, 4 months, 9 months and 21 months. The primary outcome will be the difference between groups in the change in students' body mass index at 9 months after the baseline investigation. The secondary outcomes will include the differences between groups in the changes in anthropometric measures, diet, physical activity levels and other measures at the follow-up visits. A variety of process evaluation methods will be used to evaluate the implementation process of the complex intervention.