Association of Evening Eating with Sleep Quality and Insomnia among Adults in a Brazilian National Survey.

Objective  To examine the association of evening eating clock time, its elapsed time to the midpoint of sleep (TEM), consumption of caffeine and sugary foods, and reporting dinner as the largest meal with sleep quality indicators and insomnia. Methods  Participants ( n  = 2,050;18-65y) were part of population-based research, with virtual data collection. Logistic regression models were fitted to assess differences in the ORs(95%CI) of sleep duration < 7 hours, sleep latency > 30 minutes, poor sleep quality, and insomnia (outcomes) with the evening diet-related variables. Linear regression analyses evaluated differences in sleep duration and latency associated with the same variables. Restricted cubic splines were used to study the shape of the association of eating event clock time and TEM with sleep duration and latency. Results  Each additional hour of evening eating clock time and of the TEM, respectively increased and decreased, the odds of sleep duration < 7/h [OR(95%CI):1.30(1.20,1.40); OR(95%CI):0.51(0.47,0.56)], sleep latency > 30min [OR(95%CI):1.14(1.07,1.22); 0.88(0.83,0.94)], poor sleep quality [OR(95%CI):1.21(1.13,1.30); 0.80(0.76,0.85)] and insomnia [OR(95%CI):1.12(1.04,1.20); 0.89(0.84,0.95)]. We found a dose-response association between evening eating (clock time and TEM) and sleep duration. The shortest latency was seen when evening eating was ∼20:00 and ∼7-8 hours before the midpoint of sleep. Participants who reported dinner as the largest meal and consumed caffeine and sugary foods/beverages after 18:00 presented higher odds of sleep duration < 7 hours, poor quality, and insomnia. Conclusions  Our findings indicate that an early-eating schedule has beneficial sleep effects and that it will be necessary to consider evening eating patterns and timing, along with the existing sleep and circadian hygiene, to improve sleep quality and circadian health.