Late Night Eating and Sleep

By Dr. Ryan Neely, Ph.D.

You sit down at your desk and the teacher hands out the final exam. Your stomach drops when you realize that you read the wrong textbook - you have no idea how to answer any of the questions. Also, you forgot to put on your pants that morning. Everyone in the class is staring at you. All of a sudden you wake up - it’s 2:30 AM, it was all just a nightmare. As you turn over to go back to sleep your stomach rumbles - those spicy enchiladas you ate right before bed aren’t sitting well. Could the nightmare and your indigestion be linked?

Food and Dreaming

There is a common notion that late night eating, or eating certain foods, can cause nightmares. A 2015 study of over 300 participants found that 17.8% reported associations between late-night eating and bizarre or disturbing dreams1. Interestingly, dairy was the most commonly reported culprit. This bad reputation could be why the British Cheese Board commissioned a study to examine the link between cheese and dreams - the results however were never formally published. In the scientific literature, there is little evidence to corroborate or disprove these anecdotal experiences. Nielsen et al. cite a single study reporting that eaters of organic foods reported more frequent dream recall than habitual eaters of fast foods2. A separate study of lucid dreamers found that eating fish correlated with lucid dream frequency, while eating chili correlated with awareness of the state between wakefulness and sleep3. However, the sample sizes for these studies were small, and the results should be considered preliminary. 

Food and Sleep Quality

While the link between food and dreaming remains poorly understood, the association between food and sleep disturbances has received more attention. A recent study of healthy adults found a negative correlation between late night eating, especially high-caloric foods, and several variables of sleep quality - suggesting that late night eating patterns could be disturbing your sleep4. Based on these results, having your last meal or late night snack at least an hour or more before bed can help to minimize the time it takes to fall asleep. Interestingly, a separate study found that what you eat late at night matters - participants who ate a late-night kabab (a slowly-digestible protein and fat-rich meal) experienced more sleep disturbances than participants who had a late night dessert (a quickly digested, high sugar meal)5. Furthermore, if you already have sleep difficulties, late-night eating can make them worse. For example, for individuals with sleep apnea, late night eating habits can increase the time it takes to fall asleep, the occurrence of waking in the night, and increase apnea-hypopnea index6. 

Conclusions

Although the link between funky cheese and nightmares isn’t so well established, it is clear that eating close to bedtime (think ~60 minutes or less) can have a significant impact on sleep quality - especially if you are already prone to sleep disturbances. Although it’s not exactly clear why food impacts our sleep, remember that the gut exerts a powerful influence on the brain, and has a complex nervous system of its own. As researchers learn more about what’s known as the gut-brain axis, it becomes more and more obvious that what happens in our digestive tract has meaningful consequences for our cognitive functions, including sleep. Additionally, it has also been suggested that increases in core body temperature caused by eating late at night could be responsible for a vicious cycle of sleep disturbances, dysregulated eating, and metabolic function7. In general, if you can avoid late dinners or pre-bed snacks, you can help eliminate these negative impacts of late night food on sleep quality. However, if you just can’t resist, maybe lay off the kabab and stick with a cookie!

References:

1. Nielsen, T. and Powell, R.A., 2015. Dreams of the Rarebit Fiend: food and diet as instigators of bizarre and disturbing dreams. Frontiers in psychology, 6, p.47. 
2. Kroth, J., Briggs, A., Cummings, M., Rodriguez, G. and Martin, E., 2007. Retrospective reports of dream characteristics and preferences for organic vs junk foods. Psychological reports, 101(1), pp.335-338.
3. Biehl, J., 2022. Foods and substances influencing (lucid) dreams. International Journal of Dream Research, pp.224-234.
4. Crispim, C.A., Zimberg, I.Z., dos Reis, B.G., Diniz, R.M., Tufik, S. and de Mello, M.T., 2011. Relationship between food intake and sleep pattern in healthy individuals. Journal of clinical sleep medicine, 7(6), pp.659-664.
5. Ucar, C., Özgöçer, T. and Yıldız, S., 2021. Effects of late‐night eating of easily—or slowly—digestible meals on sleep, hypothalamo‐pituitary‐adrenal axis, and autonomic nervous system in healthy young males. Stress and Health, 37(4), pp.640-649.
6. Lopes, T.D.V.C., Borba, M.E., Lopes, R.D.V.C., Fisberg, R.M., Lemos Paim, S., Vasconcelos Teodoro, V., Zalcman Zimberg, I. and Crispim, C.A., 2019. Eating late negatively affects sleep pattern and apnea severity in individuals with sleep apnea. Journal of Clinical Sleep Medicine, 15(3), pp.383-392.
7. Brown, R.F., Thorsteinsson, E.B., Smithson, M., Birmingham, C.L., Aljarallah, H. and Nolan, C., 2017. Can body temperature dysregulation explain the co-occurrence between overweight/obesity, sleep impairment, late-night eating, and a sedentary lifestyle?. Eating and Weight Disorders-Studies on Anorexia, Bulimia and Obesity, 22, pp.599-608.