Testing a Mobile App for Participatory Research to Identify Teen-Targeted Food Marketing: Mixed Methods Study

Mobile apps are not only effective tools for promoting health to teenagers but are also useful for engaging teenagers in participatory research on factors that influence their health. Given the impact of food marketing messages on teenagers' food attitudes and consumption choices, it is important to develop effective methods for capturing the food advertisements targeted at this population to assess their content.

The aim of this study was to test the feasibility and usability of a mobile app, "GrabFM!" ("Grab Food Marketing!"), designed for teenagers to facilitate monitoring of self-identified targeted food marketing messaging.

A mixed methods approach, including quantitative user response rates and qualitative focus group discussion feedback, was used in the evaluation process.

A total of 62 teenagers (ages 13-17) completed GrabFM! app pilot testing over a 7-day data collection period. Teenagers submitted a total of 339 examples of food marketing, suggesting high feasibility for the app. Participants also took part in focus group discussions about their experience, providing positive feedback on usability, including ease of use and design aesthetic appeal.

The GrabFM! app had high feasibility and usability, suggesting its efficacy in capturing accurate data relevant to the teenage population's experience with food marketing messaging.