Exploring reactivity to EMA and consumer-grade wearable measurement of physical activity among individuals with binge-eating spectrum disorders.

OBJECTIVE: Advances in wearable technology offer new opportunities to comprehensively and objectively measure exercise in eating disorder (ED) samples; however, concerns persist that consumer-grade wearables may increase ED symptoms. To date, no studies have explicitly reported on reactivity to sensor-based activity assessment in binge-spectrum ED samples, limiting information on potential risks in this population. METHOD: Adults with binge-spectrum EDs (N=30; 43.3% male) completed the Eating Disorder Examination (EDE) Interview and 28 days of 6-daily ecological momentary assessments (EMA) while wearing a consumer-grade activity tracker. We compared EMA-reported symptoms to EDE report and examined short-term variability (within-week) and long-term change (over 28 days) in physical activity (PA; steps, moderate-vigorous PA [MVPA], total PA) and ED symptoms (loss-of-control [LOC] eating, dietary restraint, body dissatisfaction, maladaptive exercise episodes). All models covaried for sex, BMI, and EMA compliance. RESULTS: Across the EMA period, participants reported fewer maladaptive exercise episodes (Mdiff=-26.43, p<.001), non-maladaptive exercise (Mdiff=-16.83, p=.020), and other compensatory behaviors (Mdiff=-15.90, p=.007), and episodes of dietary restraint (Mdiff=-7.97, p=0.001) compared to EDE-report. Daily odds of LOC eating (OR=0.96, p=.014) and dietary restraint (OR=0.92, p<.001) decreased over the EMA period. Variability in dietary restraint was significantly greater in week 1 vs. week 4 (p=.047). Accelerometer-measured PA reduced by ∼6 sec/day (β=-0.100, p=.007). CONCLUSION: Findings suggest limited reactivity to wearable monitoring in binge-spectrum EDs. Decreases in some ED symptoms may reflect increased awareness, behavior change, or over-reporting at baseline. Minimal changes in ED symptoms and PA support feasibility of wearables in binge-spectrum ED research, with low risk of harm.