Smartphone dependence predicts poorer mental health outcomes, eating behaviors, activity levels, and body image: a cluster analysis of Brazilian university students

Abstract Objective: Excessive smartphone use has been linked to mental health impairments and may potentially alter human behavior. These effects are particularly pronounced among younger individuals, with university students being especially susceptible to the negative influences of smartphone use. Methods: This observational, cross-sectional study was conducted in a sample of 781 Brazilian university students. We assessed socio-economic variables, smartphone addiction, depression, anxiety, stress outcomes, eating behavior, body image satisfaction, and self-reported physical activity. Multivariate analysis of variance (MANOVA) and chi-square tests were performed to compare continuous and categorical variables between genders. K-means clustering was used to identify participant profiles based on various self-reported variables, with differences between clusters validated using the Z-test and the silhouette coefficient. Results: Three clusters were identified. Cluster 1 featured participants with a significant disparity between their perceived and desired body image, higher scores on eating disorders, smartphone addiction, and mental health questionnaires, and lower levels of physical exercise. Cluster 2 consisted of older participants who scored lower for smartphone addiction and mental health and had a higher body mass index (BMI). Cluster 3 included younger participants with a smaller Silhouette Scale disparity, lower eating disorder scores, and lower BMI. Smartphone addiction showed significant associations with eating disorders in the overall eating disorders classification (χ² = 13.4; p < 0.001), bulimic behavior (χ² = 20.0; p < 0.001), and social pressure to eat (χ² = 4.3; p < 0.001). It also negatively correlated with physical exercise (χ² = 5.7; p = 0.017), but not with dieting concerns (χ² = 0.23; p = 0.688). Conclusion: Smartphone addiction is associated with eating disorders, stress, depression, anxiety, and lower levels of physical activity.