Food is one of the cornerstones of well-being. But food and food-related decisions are sometimes experienced as difficult or stressful (Mennell et al., 1992) due to a lack of appropriate food knowledge (Colatruglio & Slater, 2014). In this context, mobile apps are flourishing in order to help people make healthier food choices (Flaherty et al., 2019). While the literature on mobile food applications is rich in the health field for their potential to change dietary behaviors (Covolo et al., 2017; Gilliland et al., 2015; Mateo et al, 2015; Mendiola et al., 2015; Michie et al., 2017; McKay et al., 2018; Palacios et al., 2018), there is limited research on how consumers engage with them (Bezançon et al., 2019; Doub et al., 2015; Gilliland et al., 2015; Flaherty et al., 2018, 2019; Samoggia & Riedel, 2020).

In this paper, we ask: how can we better understand the consumer engagement process for nutritional apps? Using data from 15 semi-structured interviews with users of the French nutritional app Yuka, we conducted thematic analysis, applying a lens of affordance theory (Gibson 1977).

Proposed by Gibson (1977), the concept of affordances designates the potentialities of action perceived by the individual, resulting from an interaction between the latter and their environment. Affordances are an analytical tool to explore the complex relationship between the individual and technology (Hutchby, 2001). Our data and analysis helped us to arrive at a model of engagement based on affordances, in which we examine the impact that emotions experienced during the affordance actualization stage has on user engagement at various points of app usage.

Through our research, we highlight the dynamic nature of engagement. As users attempt to actualize affordances offered by nutrition apps, emotional mechanisms influence (re)adjustments in usage, which in turn influence modes of engagement.