BACKGROUND
School food services, including cafeterias and canteens are an ideal setting in which to improve child nutrition. Online canteen ordering systems are increasingly common and provide unique opportunities to deliver choice architecture strategies to nudge users to select healthier items. Despite evidence of short-term effectiveness, there is little evidence regarding the long-term effectiveness of choice architecture interventions, particularly those delivered online.
OBJECTIVE
To determine the long-term effectiveness of a multi-strategy behavioural intervention (‘Click & Crunch’) embedded within an existing online school lunch ordering system on the energy, saturated fat, sugar and sodium content of primary school students’ lunch orders 18 months after baseline.
METHODS
A cluster randomized controlled trial that involved a cohort of 2,207 students (aged 5-12 years) from 17 schools in New South Wales, Australia. Schools were randomized to receive either a multi-strategy behavioural intervention or control (usual online ordering only). The intervention strategies ran continuously for 14-16.5 months until the end of follow-up data collection. Trial primary outcomes (i.e. mean total energy, saturated fat, sugar and sodium content of student online lunch orders) and secondary outcomes (i.e. the proportion of online lunch order items that were ‘Everyday’, ‘Occasional’ and ‘Caution’) were assessed over an eight week period at baseline and 18-months follow-up.
RESULTS
16 schools (94%) participated in the 18-month follow-up. Over time, from baseline to follow-up, relative to control orders, intervention orders had significantly lower energy (-74.1kJ; 95%CI -124.7, -23.4; P=.006) and saturated fat (-0.4g; 95%CI -0.7, -0.1; P=.003), but no significant differences in sugar or sodium content. Relative to control schools, the odds of purchasing ‘Everyday’ items increased significantly (OR=1.2; 95%CI 1.1, 1.4; P=.009, corresponding to a +3.8% change) and the odds of purchasing ‘Caution’ items significantly decreased among intervention schools (OR=0.7, 95%CI 0.6, 0.9; P=.002, corresponding to a -2.6% change). There was no between-group difference over time in canteen revenue.
CONCLUSIONS
The findings suggest that there are intervention effects up to 18-months post baseline in terms of decreased energy and saturated fat content and changes in the relative proportions of healthy and unhealthy food purchased for student lunches. As such, this intervention approach may hold promise as a population health behaviour change strategy within schools.
CLINICALTRIAL
The trial methods were prospectively registered (ACTRN12618000855224) and the 18-month follow-up was conducted in accordance with these registered procedures.
The long-term effectiveness of a multi-strategy behavioural intervention to increase the nutritional quality of primary school students’ online lunch orders: 18-month follow-up of the ‘Click & Crunch’ cluster randomized controlled trial (Preprint)
