Dan’s Plan Food on Sleep

Does What You Eat Today Affect How You Sleep Tonight? Yes

Dan's Plan Food on Sleep

As a researcher who studies the relationship between sleep and eating, I frequently get asked about how diet affects sleep. Should I avoid carbs at night? When should I eat protein and fats? What should I eat to get great sleep? While there is a growing body of evidence that sleep time and quality impact eating behaviors, there is less research on how the food choices we make today affect the quality of sleep we get tonight.

Recently, research by Marie-Pierre St-Onge and colleagues, published in the Journal of Clinical Sleep Medicine (1), evaluated whether sleep is modified in response to changes in dietary intake across the day. The study kept healthy participants in an inpatient unit, so there was a high degree of control to record what the participants ate and how they slept. During the first 4 days, the researchers gave the participants a controlled diet and monitored their sleep in response to what they ate. On day fifth day, however, the participants were allowed to choose their own food, and on that night, sleep changed: it took longer for the participants to fall asleep, they had less deep sleep and more arousals across the night.

So, what dietary factors predicted these changes? The three most notable factors were the consumption of dietary carbohydrate, fiber, and saturated fat. What did what? More fiber intake on the eat-anything-you-want day associated with positive sleep changes, including less shallow sleep and more deep sleep. Saturated fat and sugars, on the other hand, didn’t fare well. Increases in saturated fat, for instance, associated with less deep sleep, while more sugar and non-fiber carbohydrates associated with more arousals during slumber. While the study at hand doesn’t answer all questions on the subject, it does give us insight into how elements of diet might affect aspects of sleep quality.

Interpreting this information further, what we now see are signs of a potential feedback loop: certain changes in sleep duration and quality – including reductions in deep sleep and REM sleep – associate with increases in hunger and energy intake from fat and energy-dense forms of carbohydrates, like sugars (2). Eating more saturated fat and sugar within your day may then, in turn, negatively affect aspects of sleep quality at night. It’s just one other reason to maintain a healthy diet high in fiber, lower in certain fats, and low in sugar: a healthy diet may help you get better sleep, and better sleep may help you maintain a healthier diet.


  1. St-Onge, M. P., et al., (2015). Fiber and Saturated Fat Are Associated with Sleep Arousals and Slow Wave Sleep.Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine.
  2. Shechter, Ari, et al. (2012). Alterations in sleep architecture in response to experimental sleep curtailment are associated with signs of positive energy balance. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.



  • steven

    Obviously this is a great step in the right direction, but the study is very primitive–as evidenced by lumping all sat. fats and sugars together (i.e. i would assume sat. fat/sugar combo from steak and an apple would be diff than ice cream sunday). Along that same note, did they analyze the effect from sat. fats/sugar when controlling for fiber?

    • danpardi

      Hi @disqus_WEvXijxICH:disqus I have written about the importance of distinguishing fat subtypes in the past (link below), but this was a big step forward in this area since many of the other studies conducted used self reported food intake. In this case, food intake was closely monitored and the researchers did distinguish between fat types. This was a big step forward but there is more work to do. You’re right, there may be importance differences between different saturated fat types (palmitic acid vs lauric acid, for example). We see important differences elsewhere so why not here (again see article below). It is possible that this research group could do a post hoc analysis on this dataset but I suspect they don’t have the statistical power to unearth differences. But now that we see that saturated fat is a significant variable to affect sleep architecture, subsequent investigation could look at types of saturated fat to explore possible distinctions.

      This research group noticed a significant impact on sleep when subjects went from controlled diet to ad libitum. They had less slow wave sleep and longer time to sleep onset. Then the researchers did a regression analysis (so yes, controlled for other factors while observing the effects of another) to assessed the various contributions to this effect based on fat types, sugars, non-sugar carbohydrates, fiber, etc and the results I wrote about above were found.