A cluster randomised controlled trial of the impact of a multi-strategy behavioural intervention on the nutritional quality of secondary school student food purchases from online canteens.

The aim of this study is to assess the effectiveness of integrating consumer behaviour strategies (including menu labelling, item positioning, tailored feedback, and prompts) into an online canteen ordering system, to improve the nutritional quality of foods purchases by secondary school students via online canteens. This study will employ a clustered randomised controlled trial design. Ten NSW secondary schools with an existing online canteen ordering system will be randomised to receive either a consumer behaviour intervention or control (online canteen ordering only). All users of an online canteen at intervention schools will receive a consumer behaviour intervention that will be integrated into the school's existing online canteen ordering system, for 2 months. Online canteen ordering systems allow users to login to a website to access the school's canteen menu. Users are able to select and pay for food and drink items, which are processed by the canteen and supplied to students during breaks. 1. Labelling: Each item on the online menu will be labelled with a coloured symbol. The labelling system is based on the NSW Healthy School Canteen Strategy. Small symbols will appear next to each menu item; a green circle for “Everyday” foods; an amber circle for “Occasional” foods; and a red symbol for “Should not be sold” foods. 2. Positioning: Menus items will be ordered to give healthy items positions of greatest prominence. This will occur at the food category level (e.g. Drinks) and at the item level (e.g. Strawberry Flavoured Milk). The healthiest food categories / items will be positioned first. Where there are multiple flavours of an ‘Occasional’ foods (e.g. multiple flavours of chips), users will be required to first ‘click’ on the item before the full list of flavours are displayed. 3. Feedback: Prior to each lunch order being confirmed within the online ordering system, the user will receive feedback summarising the nutritional content of the order. This will take on the form of a pie chart displaying the proportion of ‘Everyday’ vs ‘Occasional’ foods selected and explanatory text. Users will have the option to amend or modify their order prior to purchasing. 4. Prompts: When a user selects an “Occasional” or “Should not be sold” hot food item, the user will receive a prompt to include a healthy add-ons (e.g. water and/or fruit or vegetable snack). The labels will be manually added to the online menus by the online canteen provider (based on a template provided by the research team). The online canteen provider will reprogram the website of intervention schools to automatically apply the positioning and feedback strategies to online menus based on the assigned label. The prompts will be manually added by the online provider. The research team will also provide the canteen managers from intervention schools with a menu feedback report. This feedback report will classified according to the NSW Healthy School Canteen strategy and each menu item will be categorised as 'Everyday', 'Occasional' and 'Should not be sold', by a research dietitian. The feedback report will also include graphical feedback comparing the canteen menu to the recommendations of the NSW Healthy School Canteen Strategy (i.e. 'Everyday' foods should comprise at least 75% of the menu, and 'Should not be sold' foods should be removed from the menu).