Eating or drinking less than 1 hour before bedtime was associated with increased risk of wake after sleep onset, a key symptom of chronic insomnia that significantly correlates with poor sleep quality.
Eating or drinking less than 1 hour before bedtime may significantly increase risk of inefficient sleep and trigger compensatory increases in sleep duration, according to study findings published yesterday in the British Journal of Nutrition.
In practicing healthy sleep, sleep hygiene recommendations typically advise against electronic screen usage, using the bedroom for any activities besides sleep or intimacy, and eating or drinking before bed, particularly large or spicy meals, alcohol, and caffeinated or carbonated beverages.
However, researchers noted that clinical findings exploring the impact of mealtime on sleep have generated conflicting findings, with many studies lacking a reference time of when nighttime eating occurs in relation to bedtime.
Seeking to further assess the association between sleep quality and eating before bedtime, researchers conducted an analysis of data derived from the American Time Use Survey, a nationally representative sample of US residents aged 15 or older, between 2003 to 2018 (N = 124,239; 53% women; 59% aged ≥ 50; 69% non-Hispanic White).
Participants’ weekday/weekend activities were recorded during a 24-hour period, with gender-stratified associations between eating or drinking evaluated at less than 1 hour, less than 2 hour, and less than 3 hour timeframes before bedtime, with sleep duration and wake after sleep onset (WASO) greater than 30 minutes, a key symptom of chronic insomnia that significantly correlates with poor sleep quality.
“Reported by 5% to 10% of adults, difficulty to maintain sleep is an insomnia symptom characterized by polysomnography as WASO greater than or equal to 30 minutes, is more common among older adults and women,” explained the study authors. “Poor mental health and physical morbidity have been associated with WASO in pediatric, pregnant, adult, and older adult populations.”
Among the study cohort, mean (SE) sleep duration was 8 (0.006) hours, and eating or drinking 1 hour prior to bedtime was reported by 6.4% of participants. Incidence of eating or drinking 1 hour before bedtime declined along increasing age categories for both men and women.
Male and female participants who ate or drank 1 hour prior to bedtime were found to be at more than 2 times greater risk of WASO than those who did not (women: odds ratio [OR], 2.03, 95% CI, 1.66-2.49; men: OR, 2.64; 95% CI, 2.08-3.36).
However, compared with men and women who did not eat or drink 1 hour before bedtime, those who did had 35 minutes (95% CI, 30-39) and 25 minutes (95% CI, 21-29) longer sleep duration on weekdays, and 31 minutes (95% CI, 25-38) and 15 minutes (95% CI, 9-21) longer sleep duration on weekends. Overall, eating or drinking less than 1 hour prior to bedtime was associated with longer weekdays sleep duration.
“As the interval of eating or drinking prior to bedtime expanded, odds of short and long sleep durations and WASO decreased,” noted researchers.
Overall, they found that eating or drinking before bedtime led to longer sleep with more awakenings, which is less efficient.
As the cross-sectional data cannot prove causal pathways, researchers concluded that prospective research to assess for any underlying causative pathway is warranted, as well as investigations on specific food and beverages in relation to sleep duration and quality.
"These findings suggest that earlier timing of eating or drinking in relation to bedtime—between 4-6 hours—increases the likelihood of optimal sleep duration," they wrote.
Iao SI, Jansen EC, Shedden K, et al. Associations between bedtime eating or drinking, sleep duration and wake after sleep onset: findings from the American Time Use Survey. Br J Nutr. Published online September 13, 2021. doi:10.1017/S0007114521003597