Diet and fitness apps are often promoted in university and college settings and touted as a means to improve health with little attention given to unanticipated negative effects, especially among those at risk for or with eating disorders.

Few researchers have studied how these apps affect women with eating disorders in university and college settings. This research investigates the unintended negative consequences of engaging with these tools.

Data collection sessions comprised three components conducted with 24 participants: survey (demographic and eating disorder symptoms), think-aloud exercise and semi-structured interview. Thematic analysis was used to analyse data.

Participants reported that diet and fitness apps trigger and exacerbate symptoms by focusing heavily on quantification, promoting overuse and providing certain types of feedback. Eight themes of negative consequences emerged: fixation on numbers, rigid diet, obsession, app dependency, high sense of achievement, extreme negative emotions, motivation from ‘negative’ messages, and excess competition. Although these themes were common when users’ focus was to lose weight or eat less, they were also prevalent when users wanted to focus explicitly on eating disorder recovery.

Unintended negative consequences are linked to the quantified self movement, conception of appropriate usage, and visual cues and feedback. This paper critically examines diet and fitness app design and discusses implications for designers, educators and clinicians. Ultimately, this research emphasises the need for a fundamental shift in how diet and fitness apps promote health, with mental health at the forefront.