For many, the holiday season is a time of celebration, connection, and indulgence. Yet for many of us, it also brings an uptick in rich meals, sugary desserts, festive drinks, and late nights – holiday excess that wreaks havoc on our sleep. If you’ve ever wondered why you feel groggy or even exhausted despite doing comparatively little during these days, here is your answer: certain foods and alcohol negatively impact our digestive system – and in turn our sleep. Understanding how and why this happens can help us enjoy the festivities while still waking up refreshed, ready to embrace the season and all its joyful chaos.
Let’s start with alcohol. Some people may believe a festive drink before bed will help them fall asleep faster, and in fact, alcohol does have sedative properties that can reduce the time it takes to drift off. However, research shows this initial effect is misleading – alcohol disrupts the natural pattern of sleep, particularly by reducing rapid eye movement (REM) sleep, which is essential for memory consolidation and emotional regulation. A systematic review of multiple studies found that even low doses of alcohol negatively impact REM sleep and fragment the rest of the night’s sleep cycles (1). In other words, while you may fall asleep quickly after a few holiday drinks, the sleep you get is often less restorative.
On top of altering sleep stages, alcohol can cause increased wakefulness later in the night and reduce overall sleep quality. Higher consumption before bedtime has been linked to more frequent awakenings, increased daytime sleepiness, and poorer subjective sleep quality, even when objective measures of sleep don’t change dramatically (2). This is because your body works overtime to metabolise alcohol, and as the sedative effect wears off, it can trigger lighter, more fractured sleep. In addition, alcohol relaxes the throat muscles, which can exacerbate snoring or symptoms of sleep apnea, further undermining rest (3).
Rich holiday foods can also contribute to sleep disruption. Large or fatty meals take longer to digest, often triggering discomfort, acid reflux, and bloating, especially if you lie down soon after eating. The types of food we frequently eat during this time, coupled with the lack of movement as we all lounge around the living room or sit at the table for hours, put a strain on our digestive system. In fact, it is likely still hard at work come bedtime, which can prevent you from falling asleep easily or staying asleep throughout the night. Late-night eating also affects blood sugar levels, which in turn can influence the sleep-wake cycle and lead to more nighttime awakenings or restless sleep (4). Even if you aren’t experiencing obvious digestive discomfort, a heavy meal can subtly raise your heart rate and metabolism right at the time when your body is trying to shift into rest mode.
The combination of excess food and alcohol compounds these effects. Overeating can make your body more sensitive to the disruptive effects of alcohol, and both can lead to dehydration, frequent bathroom trips, and increased nighttime awakenings. Toss in altered daily schedules, social jet lag, and holiday stress, and it’s no wonder many people find themselves feeling groggy, irritable, or run down during the festive season.
The good news is that small adjustments – like eating earlier, choosing lighter meals, spacing out alcoholic drinks with water, and maintaining a consistent bedtime routine – can significantly improve your ability to sleep well through the holidays. After all, quality sleep is foundational not just for energy and mood, but also for immunity and overall wellbeing – things we all want to protect as we head into the new year.
(1) Gardiner C, Weakley J, Burke LM, et al. The effect of alcohol on subsequent sleep in healthy adults: A systematic review and meta-analysis. Sleep Med Rev. 2025;80:102030. doi:10.1016/j.smrv.2024.102030. https://pubmed.ncbi.nlm.nih.gov/40362779/
(2) Strüven A, Schlichtiger J, Hoppe JM, Thiessen I, Brunner S, Stremmel C. The Impact of Alcohol on Sleep Physiology: A Prospective Observational Study on Nocturnal Resting Heart Rate Using Smartwatch Technology. Nutrients. 2025;17(9):1470. Published 2025 Apr 26. doi:10.3390/nu17091470. https://pubmed.ncbi.nlm.nih.gov/39631226/
(3) Bryan, L. Alcohol and Sleep. The Sleep Foundation. Updated October 23, 2025. https://www.sleepfoundation.org/nutrition/alcohol-and-sleep
(4) Wenk, G. How Diet Affects Sleep. Psychology Today. Posted February 20, 2023. https://www.psychologytoday.com/us/blog/your-brain-on-food/202302/how-diet-affects-sleep