How Everything You Eat (From What and When) Affects Your Sleep

Sleep affects everything from your energy levels and muscle recovery to appetite control and immune system health. You can't live without it. All the choices you make throughout the day come back to affect your sleep at night, including what you eat and when you eat it. As you gain a better understanding of how food affects your sleep, you can make food choices that support the recommended seven to nine hours of sleep.

Meal Timing
When you eat, including the spacing and regularity of your meals, you either support or detract from your circadian rhythms. Circadian rhythms are biological and physiological processes that control many of the body's functions that run on a regular 24-hour schedule, including the sleep-wake cycle. A study published in Current Biology found that a five-hour delay in meal timing altered the circadian rhythms. While the delay didn’t directly affect the central “circadian clocks,” it altered peripheral clocks enough, those that involve adipose (fat) tissue and glucose levels, to cause daytime sleepiness in participants. Regularly timed and spaced meals keep the circadian rhythms synchronized so you not only feel hungry at the right times, but the body prepares to shut down for the day at the correct time too.

Meal Composition
You may have already experienced some of the ways in which food can affect your ability to sleep. For example, indigestion brought on by a late night fast food run can make it hard to fall or stay asleep. But, discomfort isn't the only way food can affect your sleep cycle. A study published in the Western Journal of Nursing Research explored how food affects sleep latency and efficiency with some surprising, and some not so surprising, results. Sleep latency is the amount of time it takes from the moment you lay down in bed until you fall asleep. Sleep efficiency is a measure of the total hours spent in bed versus the actual hours slept. The study found that participants with high-protein diets, especially those with high tryptophan levels, showed better sleep efficiency. They woke less often during the night. Tryptophan may sound familiar as it's found in the turkey that gets blamed for many post-Thanksgiving "comas." Many other food sources contain tryptophan, but it's actually the body’s use of tryptophan to make serotonin that makes you feel sleepy. Serotonin regulates mood by making you feel calm, relaxed, and, of course, sleepy. The same study found that when participants ate meals high in carbohydrates they a shorter sleep latency (they fell asleep faster). Their results supported an earlier study, which found that carb-rich meals positively affected body temperature, heart rate, and the circadian rhythms. So what does that mean for sleep-supportive eating? We suggest a diet that includes a balance of vegetables, fruit, and whole grains for carbohydrates and lean proteins for tryptophan and other sleep-inducing amino acids, proteins, and hormones. Try to eat your evening meal earlier in the evening to prevent indigestion.

What About Bedtime Snacks?
Even if you’re able to get comfortable on your mattress, an empty stomach may get in the way of high-quality sleep. However, extreme hunger can too. If you absolutely need a late-night snack, reach for a small serving of healthy foods that promote sleep. For example, the calcium found in dairy products, bananas, and almonds contain nutrients used to make the powerful sleep hormone melatonin.

You can get better sleep when you time your meals right and eat the healthy foods your body needs to support your sleep cycle. It might take a few changes to your diet, but it will be worth it for the sleep and health gains that follow.