P100 Can extending the time between last meal of the day and bedtime improve sleep regularity? A pilot study in Australian adults

Abstract Sleep regularity is important for health and wellbeing. Food intake close to bedtime negatively impacts sleep regularity by lengthening sleep onset and reducing sleep duration. Extending the time between the last meal of the day and bedtime could improve sleep regularity. This pilot study investigated whether extending the time between last meal and sleep onset through time-restricting eating (TRE) impacts sleep regularity. Adults (n=6, 18-38 y, 5 female) completed 2-weeks baseline with usual eating timing followed by 6-weeks of TRE (10-hours between first and last meal, with last meal by 8pm), and a daily sleep diary. The standard deviations of sleep onset and sleep duration were calculated to indicate sleep regularity. Interviews were conducted to understand lived experience of TRE and sleep regularity. A one-way ANOVA revealed differences in time between last meal of the day (p=0.04), with 2.04hours between last meal and sleep onset during baseline and 4.00hours during TRE. There were no significant differences in sleep variables between baseline, 3-weeks TRE, and 6-weeks TRE (onset p=0.54; duration p=0.85). Participants reported positive experiences of TRE on sleep, commenting that TRE is “more consistent…because if I finish eating at a certain time, then I tend to go to bed at a set time.” While there were no significant improvements to sleep regularity after TRE, participants found it easier to have a consistent sleep routine when there was a longer time between eating and sleep. The next step is to build on these findings with objective sleep measures.