Front Nutr. 2026 ;13 1823259
Background: Metabolic disorders are closely linked to sleep disturbances. Time-restricted eating (TRE) can improve metabolic disturbances, but its impact on sleep quality is insufficiently studied and recommendations regarding the eating timing in TRE are pending. Our aim was to investigate the impact of early TRE (eTRE) and late TRE (lTRE) on sleep quality in obesity.
Methods: This is a secondary analysis of the randomized crossover trial, which included 31 women with overweight and obesity. Following a 2-4 week baseline period, participants were assigned to either a two-week eTRE (eating 8 a.m-4 p.m.) or a two-week lTRE (eating 1 p.m.-9 p.m.), separated by a two-week washout phase. Sleep metrics were assessed objectively by blinded actigraphy and subjectively using Pittsburgh Sleep Quality Index (PSQI) and self-report of sleep quality. Hunger and satiety were examined using a Visual Analogue Scale (VAS).
Results: Actigraphy revealed no between-intervention differences in changes in sleep metrics, but improvements were observed within eTRE compared with baseline for sleep efficiency (p = 0.047), sleep fragmentation index (SFI) (p = 0.029), and awakening length (p = 0.043). Individuals with lowest sleep quality at the baseline showed its largest improvements in eTRE. PSQI scores and self-reported sleep quality remained unchanged between and within both interventions. There were no differences in evening hunger and satiety scores between eTRE and lTRE, and no correlations between hunger or satiety and sleep quality.
Conclusions: eTRE, but not lTRE, improved objectively assessed sleep quality, and these changes were not related to hunger or satiety. eTRE may be a more effective strategy for improving wellbeing and sleep-related health outcomes. ClinicalTrials.gov number, NCT04351672 (registered on April 17, 2020).
Keywords: chrononutrition; eating timing; hunger; satiety; sleep; time-restricted eating (TRE)