Post-intervention sustainability of time-restricted eating versus caloric restriction: a secondary analysis

Rising obesity rates necessitate sustainable weight management strategies. Current lifestyle guidelines focus on reducing caloric intake through personalized interventions to promote compliance. This secondary analysis evaluated post-intervention sustainability of time-restricted eating (TRE) versus caloric restriction (CR), hypothesizing that TRE's "watching the clock" approach may be more sustainable than CR's "watching calories." Following a 12-week supervised intervention (TRE: 8-h eating window, n = 29; CR: 15% caloric reduction, n = 26), 41 participants (75%; 24 F/17 M; 23 TRE/18 CR; age 43.1 ± 11.6 years; BMI 34.7 ± 5.4 kg/m²) completed follow-up surveys at 1, 3, and 6 months. TRE participants maintained weight across all follow-ups compared to final intervention weight. CR participants showed significant loss at 1 month (-1.6 ± 2.5 kg, p = 0.02), returning to baseline by 3 months. Both interventions had similar continuation rates (1,3,6 months: TRE: 52%, 36%, 47%; CR: 63%, 57%, 50%; p = 0.60) and recommendation rates (TRE: 81%, 85%, 86%; CR: 88%, 86%, 80%; p = 0.72). TRE participants reported improved sleep, energy, and digestion but experienced morning hunger and scheduling challenges. CR participants noted increased food mindfulness but reported tracking anxiety, cravings, and potential binge eating. Despite limitations including small sample size and self-reported weight, both self-sustained TRE and CR showed similar acceptability and weight maintenance at 3-6 months post-intervention. Clinical Trial Registration: Clinicaltrials.gov NCT04259632.