Schools and student obesity: research into school-level environmental associations and student weight-related factors

Thesis

Background: This thesis investigated the role that primary schools play in promoting healthy eating and physical activity (PA) amongst students. The socio-ecological model (SEM) to health provided the theoretical framework for understanding the different levels of influence on childhood obesity. A systematic review of the evidence was published that looked at the relationship between the school setting and rates of student overweight and obesity (O&O;). Its primary aim was to examine if there was a significant association between student Body Mass Index z-scores (zBMI) and the number of school environmental actions in place to promote healthy eating and PA amongst students.

Methods: As part of a larger-scale investigation into childhood obesity led by the World Health Organization (WHO) Collaborating Centre for Childhood Obesity in Victoria, Australia, student- and school-level data were collected using objective measures of student weight outcomes and self-report behavioural questionnaires (providing individual-level data), along with the Be Active Eat Well (BAEW) school environmental questionnaire (providing school-level data). Descriptive and regression analyses were completed to investigate statistical associations between student zBMI and results from the BAEW questionnaire, including once adjusted intermediary factors and clustering.

Results: From a sample of 715 Year 4 and 6 students across 34 primary schools, males reported a significantly higher prevalence of O&O; than females (34.3% and 28.7%, respectively) and further analyses were split by gender. Indigenous Australian students reported significantly higher rates of zBMI than non-Indigenous Australians (p-value = 0.001), but with only a small sample size (n = 23). A range of significant associations were found between individual-level factors. Fully adjusted multivariate regression models reported a significant association between student zBMI and the amount that schools did to promote healthy eating amongst female students (p-value = 0.007).

Conclusion: The number of school-level actions in place to promote healthy eating was significantly associated with student zBMI in girls. This thesis was supportive of the hypothesis that schools play an important role in the prevention of childhood O&O.; It makes a unique contribution to the evidence-base in terms of the methodology behind the study of school effects on student weight outcomes. It promotes the adoption of a socio-ecological approach to childhood obesity prevention, focused across all levels of society, and provides direction for future research and policy and legislation aimed at preventing childhood obesity in Australia and elsewhere.

Authors: Turner, K

• DOI: 10.5287/ora-qxgmnpkba
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford