SUN-699 Post-Intervention Sustainability of Time-Restricted Eating vs Caloric Restriction

Disclosure: D. Chen: None. R.A. Herrera: None. Q. Wang: None. E. Helgeson: None. N. Oldenburg: None. L.S. Chow: None. Introduction: Time-restricted eating (TRE) is an alternative option to caloric restriction (CR) for weight loss. Theoretically, TRE’s “watching the clock” might be easier than CR’s “watching calories” approach. Research comparing TRE vs CR on weight loss has been mixed; the sustainability of these dietary changes post-supervised intervention remains unknown We examined if participants in a 12 week supervised TRE vs CR sustained their dietary behaviors post-intervention. Methods: Adults 18-65 years old with a BMI > 30 kg/m2 recruited from MHealth Fairview Health System, Minnesota, were randomized to supervised TRE vs CR for a duration of 12 weeks between October 2020 and October 2023. Primary outcomes included weight loss, changes in body composition and metabolic flexibility. After the completion of the supervised intervention, participants were surveyed at 1, 3 and 6 months to evaluate if they continued their assigned dietary intervention. Results: 55 participants completed either 12 weeks of supervised TRE (n=29, 8-hour self-selected eating window) or CR (n=26, 15% reduction of daily caloric intake). Following the supervised intervention, 39 participants (71%; 22 TRE/17 CR) completed at least one follow-up survey administered at 1, 3, and 6 months post-intervention. Among survey respondents, participants reported continuing their assigned intervention at similar rates (p = 0.60): TRE (52%, 36%, and 47%) and CR (63%, 57%, and 50%) at 1, 3, and 6 months, respectively. TRE participants had mean self reported weight loss from the end of the supervised intervention to 1, 3, or 6 months post-intervention of -0.5 kg, -0.7 kg and 0 kg respectively. CR participants had mean weight loss at 1, 3 and 6 months of -1.6 kg, -1.5 kg and -2.4 kg, respectively. These trend differences were not statistically significant (p = 0.23). Among survey respondents, no difference was detected between groups (p=0.72) in rates of being likely to recommend their respective intervention to friends/family: TRE (81%, 85% and 86%) and CR (88%, 86% and 80%) at 1, 3 and 6 months, respectively. Discussion: Six months after a supervised intervention comparing TRE and CR, approximately half of participants reported maintenance of their assigned dietary intervention. While participants employing CR achieved greater weight loss, it was not significantly different compared to TRE. Participants from both groups reported satisfaction with their dietary intervention and were likely to recommend these dietary interventions to their friends or family. This study highlights the difficulty of continued weight loss via self-maintenance. Presentation: Sunday, July 13, 2025