Early time-restricted eating advances sleep in late sleepers: a pilot randomized controlled trial

Study Objectives: This study evaluated the effects of early time-restricted eating (eTRE) on shifting the timing of sleep among late sleepers. Primary outcomes included actigraphy- and sleep diary-derived sleep onset, midsleep phase, and wake time with total sleep time as a secondary outcome. Methods: Fifteen healthy adults with habitual late sleep timing were randomized to receive either eTRE or sleep and nutrition hygiene (control) via a single 30-minute synchronous video session. Participants completed an initial 1-week baseline phase followed by a 2-week intervention phase. Measures included continuous sleep monitoring and sleep and nutrition diaries. Results: Linear mixed-effects modeling demonstrated that eTRE significantly advanced sleep timing compared with controls. Self-reported sleep onset (56.1 [95% confidence interval: 20.5, 91.7] minutes), midpoint (19.5 [7.2, 31.9] minutes), and offset (42.2 [2.9, 81.5] minutes) each moved earlier in eTRE as compared with controls. Similarly, objectively determined sleep onset (66.5 [29.6, 103.4] minutes), midpoint (21.9 [9.1, 34.7] minutes), and offset (39.3 [1.3, 77.3] minutes) each moved earlier in eTRE as compared with controls. Total sleep time showed a nonsignificant increase in the eTRE group as compared with controls. Conclusions: Late sleepers who were instructed in a single session about eTRE significantly advanced their sleep timing, especially sleep onset. eTRE shows potential as a clinical strategy for advancing sleep timing in late sleepers.