The Foods You Choose Can Impact Your Sleep

Many Americans suffer from insomnia or restless sleep. Could our food intake be a factor? A new review published in the Journal of the Academy of Nutrition and Dietetics looked at how different dietary patterns and nutrients can have an impact on sleep.

“Research in our review shows that modeling your diet after the Mediterranean diet could be an effective strategy for improving sleep quality,” says Katherine Wilson, BS, one of the researchers on this study. “This means consuming primarily complex carbohydrates, polyunsaturated fats, lots of fruits and vegetables, and anti-inflammatory foods containing antioxidants and omega-3 fats.”

Foods with antioxidants include vegetables, fruits, whole grains, dark-colored beans, and tea. Foods with omega-3 fats include oily fish such as salmon, trout, and sardines.

About the Review

For the review, the researchers looked at 20 past studies on diet and sleep. Articles included in the review were ones that looked at diet and included a sleep assessment by actigraphy or polysomnography.

Actigraphy uses a motion-based wrist monitor that tracks the sleep-wake states and sleep continuity. Polysomnography uses sensors placed on the head to identify different stages of sleep.

Some of the parameters that were measured include rapid eye movement (REM) or deep sleep; sleep latency (how long it takes to fall asleep); and sleep efficiency (time spent asleep). Goals for most adults include short sleep latency, with high sleep efficiency.

“The research included in our review shows that, generally speaking, consuming more protein, fiber-rich carbohydrates, and healthier (e.g., polyunsaturated) fats is associated with having less waking during the night, more deep sleep, and taking less time to fall asleep,” says Wilson.

Overall, sleep is an important aspect of our health and deserves further study. Poor sleep can impact work productivity, concentration, and reaction time, and can negatively affect physical and mental health. Poor sleep is also linked to cardiometabolic diseases and neurodegenerative disorders.

While many people use medications or sleep aids to promote restful sleep, they often report feeling groggy the next day. If changes in dietary habits may help without side effects, it’s worth investigating the optimal dietary patterns and nutrients that can naturally promote sleep.

Nutrients and Sleep

When it comes to carbohydrates, quality matters. Some of the past research shows that a higher fiber intake was associated with greater deep sleep, while a higher sugar intake was associated with more light sleep. That means it’s better to eat more high-fiber carbs, such as whole grains, vegetables, and legumes, and fewer refined sweets, such as soda, candy, and ice cream.

Protein intake is also associated with sleep quality. Low protein diets are associated with lower sleep efficiency, while moderate protein is associated with greater amounts of REM sleep.

For dietary fat, both the amount and type can affect sleep quality. Consuming more fat is associated with shorter sleep latency. Overall, higher intakes of saturated fat may cause worse sleep quality, while polyunsaturated and omega-3 fats had better effects.

Overall, a pattern similar to the Mediterranean diet contains the right balance of nutrients for better quality sleep.

Why Sleep and Diet Are Connected

According to Wilson, the way our bodies metabolize food can affect the brain and our sleep patterns, which makes diet and sleep interrelated.

“The food you eat during your day may influence how well you sleep at night, and generally, the healthier diet you have the better you may sleep,” she says.

Why certain foods influence certain aspects of sleep is still being uncovered.

“One possible explanation has to do with the melatonin and serotonin content of foods, as diets that contain more fruits, vegetables, grains, seeds, and legumes, which are all melatonin- and serotonin-rich foods, are often associated with better sleep,” says Wilson.  

Dietitian Wendy Bazilian, DrPH, MA, RDN, owner of Bazilian’s Health in San Diego, explains that melatonin is a hormone that helps regulate our circadian rhythm—our body clock.

“It sets the rhythm for our day and night,” says Bazilian. “It’s low in the morning and starts to increase in the evening, peak[s] in the middle of the night and then dip[s], but lifestyle and diet factors…can interrupt its production in the body, and we produce less with age.”

She recommends eating certain foods that naturally contain melatonin, such as tart cherries and walnuts.

Drinks That Negatively Affect Sleep

Caffeine, as found in coffee, tea, cola, energy drinks, chocolate, and some caffeine-enriched foods, acts as a stimulant. It’s great to wake you up in the morning, but too much caffeine later in the day can harm your sleep,

“Caffeine is a central nervous system stimulant that boosts energy,” says Bazilian. “It can sabotage sleep, especially if consumed within six hours of bed. For individuals who are very sensitive to caffeine, they may need to stop even earlier, as early as 12 hours before. Some people are less affected, but if you experience sleep disturbances, evaluate when you are consuming caffeine in the
day and experiment.” 

Bazilian says that alcohol may also negatively impact sleep.

“Although it may cause you to fall asleep faster, alcohol disrupts sleep cycles and can cause insomnia after a few hours,” says Bazilian. “Alcohol can also decrease melatonin production. Try to limit or avoid alcohol altogether or within three hours of bedtime ideally if you struggle with poor quality sleep.”