Self‐Reported Versus Objectively Logged Social Media Use: Implications for Measurement in Eating Disorder Research

OBJECTIVE: Self-reported frequency measures of social media use (e.g., "How often do you use social media?") are convenient, yet their criterion validity against objective behavioral data remains largely untested in eating disorder research. We compared self-reports of TikTok use with objective data extracted from TikTok datafiles. METHODS: Participants (N = 103) including individuals with diagnosed eating disorders (n = 42) completed a Likert-type self-report measure of TikTok use frequency over the past month. Objective data included the total number of TikTok videos delivered, total number of videos "liked" by participants, number of sessions, and number of "binge scroll" sessions (sessions lasting longer than 1 h). Associations were tested using Spearman correlations and negative binomial regressions. RESULTS: Self-reports were moderately to strongly correlated with objective indicators: videos delivered (ρ = 0.55), videos liked (ρ = 0.59), sessions (ρ = 0.65), and binge scroll sessions (ρ = 0.47). Importantly, objective use varied substantially within each self-report response category. For example, among participants reporting they "sometimes" used TikTok over the past month, one was delivered 99 videos whereas another was delivered 19,526 videos, representing nearly a 200-fold difference. Eating disorder diagnostic status and symptom severity did not moderate self-report versus objective correspondence; however, statistical power to detect interaction effects was limited. DISCUSSION: Self-report frequency measures of social media are meaningfully correlated with objective indicators but compress substantial behavioral variability. Clinicians and researchers should interpret self-reports cautiously, particularly when exposure magnitude is clinically relevant, and ought to consider objective data whenever possible.