More than 50% of American adults struggle to sleep well. Subpar sleep is linked to weight gain, heart disease, hypertension, diabetes, and neurodegenerative disorders such as Alzheimer’s. For years, researchers have known that poor sleep can lead to unhealthy food choices and ultimately weight gain. The worse you sleep, the worse you tend to eat, reaching for quick pick-me-ups in the form of sugar, fat, and highly processed foods. In the last decade, however, mounting evidence has revealed that the inverse is also true: What we eat affects how well we sleep.
“We’ve shown now in multiple cohort studies that individuals who have a better diet tend to have less risk of insomnia, less risk of obstructive sleep apnea, and less risk of having poor quality sleep,” says Marie-Pierre St-Onge, Ph.D., director of the Center of Excellence for Sleep and Circadian Research at Columbia University Irving Medical Center in New York City. These results are nothing to yawn at: Healthy eating’s impact on sleep is comparable to, if not more powerful than, taking sleep medications, according to a 2022 scientific review in the Journal of the Academy of Nutrition and Dietetics that analyzed data from 20 different studies.
The Best Diet for Sleep
Sleep benefits come from dietary patterns that are low in saturated fats and high in fiber, fruit, vegetables, whole grains, nuts, seeds, and legumes, according to numerous studies. One of the most recent, a 2020 study in the journal Nutrients that followed more than 400 American women for a year, found that participants whose diets were richer in whole plant foods reported better sleep at the end of the study than those whose diets contained less of these foods.
Higher intakes of fruits and vegetables predicted better overall sleep quality, fewer sleep disturbances, and higher sleep efficiency (time spent in bed actually sleeping rather than counting sheep). Each serving of beans consumed per 1,000 calories corresponded to a 55% higher sleep efficiency. An earlier study of both men and women in the journal Sleep found that participants who adhered to a plant- predominant Mediterranean diet had a 35% lower risk of developing insomnia with shortened sleep.
Why Food Matters
While the exact mechanisms behind the food-sleep connection haven’t yet been thoroughly studied, researchers point to several pathways that could explain the link. Plant foods play a critical role in the synthesis of melatonin, the hormone that the brain produces to regulate the sleep-wake cycle and promote healthy sleep. Some plant foods contain melatonin. Others are excellent sources of tryptophan, an amino acid that is only found in food and is the building block for melatonin.
“Most people hear about tryptophan, and think, Oh, turkey is high in tryptophan and that’s why we all feel sleepy after a Thanksgiving meal,” says St-Onge. “It’s not quite that simple.” Animal proteins are a source of tryptophan, but they also contain saturated fat, which studies have linked to sleep problems. For example, one 2019 study in the journal Aging and Disease found that higher habitual consumption of meat, including red meat, processed meat, and white meat, was associated with increased odds of poor sleep duration, poor sleep quality, and snoring. By comparison, plant sources of protein, such as nuts, seeds, and legumes, contain unsaturated fat, which studies link to better sleep. And other plant foods, like fruits and vegetables, help with the body’s absorption of tryptophan.
Plants may promote sleep through additional pathways, says St-Onge. They are rich in fiber and other anti-inflammatory nutrients that promote a healthier gut microbiome, which has been linked with better sleep. They also may improve sleep when replacing foods high on the glycemic index, according to a 2020 study in the American Journal of Clinical Nutrition.
The Big Picture
The idea isn’t to fixate on individual sleep “superfoods” but instead to look at the entire picture of a varied, whole-food, plant-centric diet, since so many mechanisms are at play that help facilitate a good night’s rest. Think of sleep and nutrition as a revolving cycle that keeps on giving back. “Sleeping better can help you make better food choices, which can then help you have better sleep,” says St-Onge. “When you’re well rested, everything is easier.”
The No. 1 Sleep Hack You Haven’t Heard Of
You know about sleep hygiene—strategies like turning off electronics, lowering your thermostat, and incorporating a relaxing bedtime routine to help lull you to sleep. But if you’re still struggling to fall or stay asleep, the first-line treatment according to the American College of Physicians is cognitive behavioral therapy for insomnia (CBT-I). Research shows that CBT-I is just as effective as medication in the short term and more effective in the long term, all with no side effects. You’ll work with a therapist to create new patterns and settle the thoughts keeping you up. Find a sleep therapist at psychologytoday.com, or access internet-based cognitive behavioral therapy(iCBT-I) online at Sleepio, Sleepful, or Sleepstation.
