Meal Timing

This review investigates the relationship between meal timing and sleep. Eating close to bedtime often disrupts sleep by increasing wakefulness and reducing sleep quality, especially with high-fat or oily meals. Conversely, high-glycemic foods consumed 4 hours before bed may help reduce time to fall asleep by promoting serotonin and melatonin production. Late-night eating is linked to poor sleep and conditions like sleep apnea, while regular meal patterns improve sleep duration and efficiency. These findings emphasize how meal timing and composition influence circadian rhythms, brain recovery, and overall well-being.

This cross-sectional study investigated the relationship between the time from dinner to bedtime (TDB) and sleep quality in young Japanese adults. It found that a shorter TDB (less than 4 hours) was associated with longer sleep latency (time to fall asleep) and slightly improved sleep efficiency, though the latter was less conclusive. Longer TDB (over 4.95 hours) resulted in faster sleep onset. These results suggest that eating dinner too close to bedtime may interfere with sleep onset, while waiting 4-5 hours before sleeping may optimize certain sleep parameters. The study highlights the importance of meal timing in improving sleep quality and overall health.

This study analyzed how meal timing and chronotype (morningness vs. eveningness) relate to sleep quality and anxiety among university students. Evening chronotypes with late dinner times (after 8 PM) exhibited higher anxiety levels than morning types, regardless of when they ate. However, no clear link was found between meal timing and sleep quality. Later bedtimes and poor sleep quality correlated with greater anxiety, highlighting how chronotype and meal timing influence mental health. These findings suggest the importance of meal timing and chronotype alignment for reducing anxiety and improving well-being.

This cohort study explored the relationship between meal timing, sleep duration, and obesity risk among Korean adults. Midnight snacking and high energy intake from late-night snacks were associated with a significantly increased risk of obesity. Conversely, sleeping for 8 or more hours per night was linked to a reduced obesity risk, especially among women. The findings highlight how circadian rhythms and lifestyle behaviors, such as meal timing and sleep habits, impact metabolic health. The study underscores the importance of aligning eating and sleeping patterns with the body’s natural rhythms to reduce obesity risk.

This study examined how meal timing and frequency relate to sleep quality in over 7,000 participants from the NHANES dataset. Results showed that eating meals later in the day, including breakfast and dinner, and having more frequent meals were associated with poorer sleep quality, as measured by the Pittsburgh sleep Quality Index (PSQI). These patterns disrupted circadian rhythms and led to longer sleep onset times and more sleep disturbances. The study underscores the importance of aligning eating habits with the body's natural circadian clock to promote better sleep and overall health.

This study examined how dinner timing impacts sleep architecture in healthy adults by comparing routine dinner (5 hours before bed) with late dinner (1 hour before bed). Results showed no significant differences in overall sleep architecture, but late dinner increased deep sleep (delta power) in the early part of the night, with lighter sleep observed later. The findings challenge the idea that eating close to bedtime negatively impacts sleep and suggest late dinners may enhance early-night sleep depth, though the effects diminish by morning. This provides novel insights into how meal timing affects sleep and could inform dietary recommendations for sleep disorders.

The sleep Foundation article examines the effects of eating before bedtime on sleep quality and overall health. It notes that consuming large meals or certain foods close to bedtime can lead to sleep disturbances, such as indigestion and acid reflux, which may impair sleep quality. Conversely, going to bed hungry can also disrupt sleep. The article suggests that a light snack before bed, comprising sleep-promoting foods like bananas, almonds, or dairy products, may aid sleep without causing discomfort. Maintaining a balanced diet and being mindful of meal timing are recommended to support healthy sleep patterns, which are crucial for cognitive function and brain health. These recommendations align with current nutritional guidelines and sleep research, emphasizing the importance of dietary habits in sleep regulation.

This study explored how meal timing affects human circadian rhythms, focusing on glucose levels and peripheral clocks like adipose tissue. Researchers delayed meal times by 5 hours for 10 young men and found that late meals significantly delayed the glucose rhythm and clock gene activity in adipose tissue but did not alter the master clock markers (melatonin or cortisol). This suggests that meal timing could influence circadian rhythms independently of light exposure and sleep, with implications for shift workers, those experiencing jet lag, and individuals with circadian rhythm disorders.

This review examines how meal timing interacts with sleep and circadian rhythms to influence cardiometabolic health. Eating late at night or consuming most calories in the evening is linked to disrupted sleep, weight gain, and reduced glucose tolerance. Conversely, early eating patterns aligned with circadian rhythms improve metabolism and reduce obesity risk. Irregular eating schedules, common in shift work, desynchronize the master clock and peripheral body clocks, increasing cardiometabolic disease risk. Interventions like time-restricted feeding show promise for weight and glucose control but need more research for long-term effects on sleep and health.

This study investigated how meal timing during simulated night shifts affects performance, sleepiness, hunger, and gastrointestinal discomfort in healthy young men. Participants eating at night showed impaired attention and reaction times during late-night hours, particularly around 4:00 AM, compared to those who avoided meals at night. Although skipping nighttime meals improved cognitive performance, it increased feelings of hunger and mild stomach discomfort. These findings highlight the importance of meal timing in mitigating the adverse effects of night shifts on cognitive performance and digestive health.

This study examined the impact of sleep quality, meal timing, and meal frequency on diet quality (DQ) among university students during remote learning in the COVID-19 pandemic. Using self-reported questionnaires, it found that inconsistent meal timing and irregular portion sizes were associated with poor diet quality. Students with high diet quality maintained regular meal schedules, ate earlier, and avoided late-night meals. Poor sleep quality and irregular eating patterns were common and were linked to lower DQ. The findings underscore the interaction between dietary habits, sleep, and health during lifestyle disruptions like the pandemic.

This commentary discusses how meal timing interacts with circadian rhythms to impact metabolic health. Late dinners (10 PM) increase glucose levels and reduce fat oxidation during sleep compared to earlier dinners (6 PM). These effects raise risks for obesity, type 2 diabetes, and metabolic syndrome, particularly for sedentary individuals or those with disrupted circadian rhythms. While meal timing significantly affects metabolic responses, individual factors like fitness levels and meal composition also play a role. Aligning meal timing with natural circadian rhythms offers a practical strategy to improve health and reduce disease risks.