Cluster randomized controlled trial of a consumer behavior intervention to improve healthy food purchases from online canteens.

School canteens represent an opportune setting in which to deliver public health nutrition strategies because of their wide reach and frequent use by children. Online school-canteen ordering systems, where students order and pay for their lunch online, provide an avenue to improve healthy canteen purchases through the application of consumer-behavior strategies that have an impact on purchasing decisions. We assessed the efficacy of a consumer-behavior intervention implemented in an online school-canteen ordering system in reducing the energy, saturated fat, sugar, and sodium contents of primary student lunch orders. A cluster-randomized controlled trial was conducted that involved 2714 students (aged 5-12 y) from 10 primary schools in New South Wales, Australia, who were currently using an online canteen ordering system. Schools were randomized in a 1:1 ratio to receive either the intervention (enhanced system) or the control (standard online ordering only). The intervention included consumer-behavior strategies that were integrated into the online ordering system (targeting menu labeling, healthy food availability, placement, and prompting). Mean energy (difference: -567.25 kJ; 95% CI: -697.95, -436.55 kJ; < 0.001), saturated fat (difference: -2.37 g; 95% CI: -3.08, -1.67 g; < 0.001), and sodium (difference: -227.56 mg; 95% CI: -334.93, -120.19 mg; < 0.001) contents per student lunch order were significantly lower in the intervention group than in the control group at follow-up. No significant differences were observed for sugar (difference: 1.16 g; 95% CI: -0.50, 2.83 g; = 0.17). The study provides strong evidence supporting the effectiveness of a consumer-behavior intervention using an existing online canteen infrastructure to improve purchasing behavior from primary school canteens. Such an intervention may represent an appealing policy option as part of a broader government strategy to improve child public health nutrition. This trial was registered at www.anzctr.org.au as ACTRN12616000499482.