How to eat healthy and save the planet. Development and evaluation of an evidence-based app

Abstract

Background: Food consumption affects individuals as well as our planet. How can a tailored app help people to make healthier and more sustainable meal choices? To answer this question, we contributed to the development of an evidence-based dietary app and evaluated its effects. The app offers personalized recipes and tips in order to reduce food waste and meat consumption, and increase the use of seasonal and plant-based products. Method: Using a mixed-methods approach, app usage data (N=2167) and quantitative data from a longitudinal online questionnaire (T1-T3: N=56) were combined with in-depth interviews with users (N=6) and app-developers (N=3). Findings: In the interviews, users evaluated the personalized recipe-suggestions positively. An additional search (e.g. recipes with certain ingredients) was often no longer necessary to find a suitable recipe. The app metrics showed positive correlations between frequent app usage and the motivation to reduce food waste (r=.06, p<.05) as well as the motivation to use seasonal products (r=.16, p<.01). The survey data showed that participants’ initial confidence to implement new dietary behavior was a strong predictor of the implementation of new dietary behavior after three weeks of app usage (β≥.49, p≤.01, R2 = .66). Last, the development team emphasized the benefits of an iterative approach in which regular user feedback informed the further development process of the app. Discussion: The results of this research show that it can be effective to combine health- and sustainability-focused diet interventions. These interventions should be personalized and aim to increase users’ confidence to perform new dietary behavior.