Table 1.

SWAP IT intervention components

Intervention component	Description
1. School nutrition guidelines	Schools received support to develop a school nutrition guideline outlining preferred foods to be packed in lunchboxes and guidance on how to limit the packing of discretionary food items. The guideline encouraged packing ‘recommended’ foods in the lunchbox every day in place of discretionary foods. Recommended items refer to foods and drinks from the core food groups as determined by the Australian Dietary Guidelines and Australian Guide to Healthy Eating [6]. Schools were provided with a template to assist in the development of the guidelines and encouraged to invite parents to assist with decisions regarding the content. The guideline was communicated to parents via school newsletter, school website and/or pushed to parents via the school mobile communication app prior to the second term of intervention. The school nutrition guideline addressed the identified barrier of lack of policy.
2. Lunchbox flipchart lessons	Schools and teachers were provided with a ten page flipchart for each classroom at the launch of the intervention. The flipchart features a different lunchbox sample for each week of the intervention and provides ideas for teachers to facilitate discussion on healthy lunchboxes in the classroom. The use of lunchbox flipchart lessons were designed to address child preference as a barrier to packing ‘recommended’ foods.
3. Parent communication pushed via a school mobile communication app (‘m-health’ component)	The intervention utilised an existing school mobile communication app (Skoolbag) to communicate lunchbox messages to parents/carers which address the barriers to packing a healthy lunchbox. Only active users of the school communication app were able to view the pushed intervention material. Therefore, in an effort to increase reach, parents were given instructions on how to download the school communication app at the beginning of the intervention period. In the first week of the second term of the SWAP IT intervention, eight static lunchbox themed pages (static content) were uploaded to the school mobile communication app. Additionally, parents received a push notification via the school mobile communication app once per week for 10 weeks (ten pushed messages in total). The static content and push notifications encouraged simple lunchbox swaps from common ‘discretionary’ foods to ‘recommended’ foods consistent with the dietary guidelines. Each push notification addressed a known barrier to packing healthy lunchboxes and included a “hook” (a headline designed to attract attention), pictures of lunchbox and swap examples, a 50–70 word message, a link to a video (only in selected pushes), link to the health organisation website housing additional content and an email address to request further information. For example, a pushed message may read: ‘(Hook) Veg-tastic lunchboxes: (Pushed message) Vegetables are packed with nutrients to help kids learn and play. And whilst it can be difficult to get kids to eat them you can make easy swaps to encourage greater vegetable intake at school. Set a goal to pack an extra vegetable item in your child’s lunchbox next week. For example: Swap out chips and sweet biscuits for vegetable sticks with hommus or salsa! For more great ideas to increase your child’s vegetable intake visit SWAP IT website. Once a message had been pushed to parents via the school mobile communication app, it appeared as static content on the school mobile app for parents to refer to at later stages when convenient.
4. Resources	In the first week of the SWAP IT intervention, each student received an information package containing tools and resources, including a lunchbox ideas booklet which provided easy, seasonal and low cost lunchbox ideas, ice-brick and ‘water only’ drink bottle to address the identified barriers of food safety, lack of time/ convenience, lack of knowledge, child preference and cost.