A trial of a six-month sugar-sweetened beverage intervention in secondary schools from a socio-economically disadvantaged region in Australia

Objective: This study assessed the effectiveness of a school-based intervention in reducing adolescents’ sugar-sweetened beverage (SSB) consumption and percentage of energy from SSBs. Secondary outcomes were SSB consumption within school, average daily energy intake, and body mass index z-scores. Methods: Six secondary schools located in New South Wales, Australia were recruited to participate in a six-month pilot randomised controlled trial (1:1). The intervention included components targeting the school nutrition environment, curricula and community. Outcomes were collected via online surveys, observations, anthropometric measurements and project records. Between-group differences were assessed via linear mixed models. Results: At the six-month intervention endpoint (n=862) there were no statistically significant differences between students in intervention or control schools for mean daily intake of SSBs (8.55mL; CI −26.77, 43.87; p=0.63), percentage daily energy from SSBs (0.12% kJ; CI −0.55, 0.80; p=0.72), or for secondary outcomes. Acceptability of the school-based strategies were high, however intervention fidelity varied across schools. Conclusion: While acceptable, improving fidelity of implementation and increasing the duration or intensity of the intervention may be required to reduce SSB intake. Implications for public health: Engaging parents and education stakeholders in the development phase to co-design interventions may prove beneficial in improving intervention fidelity and enhance behavioural outcomes.