10 Proven Diet Tweaks to Improve Your Sleep

Written by Dr. Shadi Zarei, Published September 2021, Updated December 2023

It's one a.m., and you're still awake, tossing and turning in your bed, begging your brain to make you sleep. An hour passes, and you're not any closer to drifting off. The thought of your alarm going off in just a few hours only makes it harder to fall asleep, leaving you wide awake."

If this situation sounds familiar, you're not alone. Insomnia, defined as difficulty falling and staying asleep, is a common condition impacting one in three adults worldwide. Insomnia can be short-term, lasting less than three months, or chronic, occurring at least three times a week for more than three months.

Many believe improving sleep is beyond their control because 'you cannot just get a new brain that sleeps well.' While it's true that you can't 'get a new brain' or directly rewire your brain for better sleep, you have the power to influence it indirectly. One effective way to do this is through your diet.

The foods you consume play a significant role in the duration and the quality of your sleep. By adopting dietary habits that promote good, restorative sleep, you can significantly improve your sleep.

In this article, we'll explore dietary changes that can improve your sleep. We'll begin by understanding the mechanics of sleep and then delve into how certain foods can disrupt or improve it. Finally, we'll present ten practical diet tweaks you can implement today for better sleep.

How does your brain make you sleep, and what role does diet play?

Your brain regulates sleep through a complex interplay of various brain chemicals, hormones, and the body's internal clock, known as the sleep/wake cycle (or the circadian rhythm). The sleep/wake cycle is an innate biological clock that cycles roughly every 24 hours, influencing when you feel awake and sleepy.

During the day, exposure to light helps keep you alert and maintains the rhythm of this clock. As evening approaches, the brain starts to produce more melatonin, a hormone that signals to your body that it's time to sleep, making you feel drowsy.

Inside the brain, different chemicals play roles in the sleep/wake cycle. When these elements work together, you experience a good, restorative sleep. But when your sleep/wake cycle is out of balance, sleep is disrupted, and sleep-related issues like insomnia can arise.

Your diet significantly affects this balance, as what you eat and drink influences the production and regulation of brain chemicals and hormones involved in the sleep/wake cycle. Depending on your dietary habits, you can either help maintain this balance or disrupt it.

Dietary items that interrupt your sleep

Certain foods and beverages can disrupt your sleep/wake cycle balance, leading to interrupted sleep. Key culprits include caffeinated items, alcohol, sugary and fatty foods and beverages. Let's delve into each of these in more detail.

How does caffeine disrupt your sleep?

Caffeine is a stimulant that keeps your brain alert by blocking the effects of a sleep-inducing brain chemical called adenosine (ah-DEN-oh-seen). Typically, adenosine levels increase throughout the day, gradually making you feel sleepier as the evening approaches.

However, caffeine disrupts this natural process by preventing the buildup of adenosine, thereby delaying the onset of sleepiness. As a result, it may take longer for you to fall asleep. Beyond reducing the amount of sleep you get, caffeine can also lower your sleep quality.

Foods and beverages containing caffeine, such as coffee, tea, soda, energy drinks, caffeine pills, and chocolate, can all impact your sleep.

Energy drinks and caffeine pills are particularly disruptive. Energy drinks combine high levels of caffeine with sugar, while caffeine pills deliver a highly concentrated dose of caffeine, both of which can significantly impair your sleep.

What can you do to mitigate the effects of caffeine on your sleep?

Stop consuming caffeinated foods and beverages eight hours before your bedtime.
Avoid consuming energy drinks and caffeine pills altogether.

How does alcohol affect your sleep?

Alcohol, contrary to caffeine, is sedating. But this doesn't mean it helps you sleep better. While it might help you fall asleep faster initially, this effect diminishes as your body metabolizes the alcohol. During this process, chemicals are produced that negatively impact your sleep in several ways.

First, these chemicals disrupt the balance of sleep-related chemicals and hormones in your brain. This imbalance leads to shorter sleep durations, reduced sleep quality, and frequent awakenings during the night.

Second, alcohol affects your breathing by narrowing the upper airway and relaxing the muscles in your throat, often causing snoring. Snoring disrupts normal breathing, depriving your brain of oxygen and preventing good, restorative sleep.

Third, alcohol can reduce your brain's responsiveness to low oxygen levels and its ability to wake you up to normalize these levels. This effect can lead to frequent breathing pauses, known as 'apnea,' significantly reducing sleep quality.

The combination of a disrupted sleep/wake cycle and breathing pauses results in shorter, less restorative sleep.

What can you do to mitigate the effects of alcohol on your sleep?

Stop consuming alcohol at least three hours before bedtime.
Avoid using alcohol as a sleep aid.

How do sugary foods and beverages disrupt your sleep?

Sugar, like caffeine and alcohol, has a disruptive effect on sleep. Diets high in sugar and saturated fat lead to lighter, less restorative sleep and more frequent awakenings during the night. Sugar impacts your sleep in several ways:

First, consuming too much sugar during the day can lead to eating late dinners. A full stomach at bedtime keeps your body, including your brain, active in digesting the food, which can delay sleep.

Second, sugar intake in the evening can provide a burst of energy, prompting more activity and making it harder to wind down and fall asleep.

Third, when you consume sugar, your body breaks it down to maintain normal blood sugar levels, a process that requires magnesium. Therefore, high sugar consumption can deplete magnesium levels, which is problematic since magnesium is essential for good, restorative sleep.

These effects underscore why sugary foods and beverages can harm your sleep.

What can you do to mitigate the effects of sugar on your sleep?

Limit eating and drinking sugary foods and beverages, particularly in the evening.
Aim to have your dinner at least three hours before bedtime, allowing your body ample time to digest the meal.

How do fatty foods and beverages disrupt your sleep?

Saturated fat, like sugar, can disrupt your sleep. A higher intake of saturated fat is linked to lighter, less restorative sleep with more awakenings during the night. Specifically, a high-fat diet leads to less slow-wave sleep, the deep, restorative phase of sleep.

What can you do to mitigate the effects of fatty food on your sleep?

Plan a diet that is low in both sugar and saturated fat.
Limit your intake of fast food and instant food products, as they are often high in saturated fat.
When preparing meals, use healthy alternatives instead of saturated fat.

Each of the dietary items discussed—caffeinated foods and beverages, alcohol, sugary and fatty foods—can individually disrupt your sleep. However, when combined, like having coffee with sugar or consuming sugary, fatty fast food in the evening, their harmful effects multiply. This synergy can significantly reduce sleep duration and worsen sleep quality.

Dietary items that improve your sleep

Now that we've discussed sleep-disrupting dietary items, let's shift our focus to some beneficial foods. We'll delve into three specific sleep-promoting foods, including fruits and vegetables, fish, and foods rich in tryptophan, that can help you have good, restorative sleep.

How do fruits and vegetables improve your sleep?

Fruits and vegetables improve your sleep because they contain sleep-promoting nutrients that maintain the sleep/wake cycle balance. First, they are rich in fibre, a nutrient linked to improved sleep duration and sleep quality.

Second, specific fruits, such as cherries and kiwifruit, contain melatonin and serotonin, two important brain chemicals for good, restorative sleep. Melatonin signals to your body that it's time to sleep, while serotonin helps calm brain activity, promoting relaxation. Cherries contain both melatonin and serotonin, and kiwifruit has high levels of serotonin.

Third, fruits and vegetables help reduce inflammation and oxidative stress, helping balance your sleep/wake cycle and improving sleep.

Due to these effects combined, a diet rich in fruits and vegetables can lead to longer sleep duration and higher sleep quality.

What can you do to increase the positive effects of fruit and vegetables on your sleep?

Incorporate a diverse range of fibre-rich foods, fruits, and vegetables into your diet.

How does fish improve your sleep?

Fish is known to promote sleep for several reasons. First, among various meats, fish has the highest level of melatonin. As previously discussed, melatonin is a brain chemical crucial for signalling your body that it's time to sleep.

Second, fatty fish, such as salmon and trout, are rich in omega-3 fatty acids. Omega-3 is essential for regulating serotonin, a brain chemical that not only influences mood but also improves sleep.

Third, fish is a good source of vitamin D, which, like omega-3, helps the brain regulate serotonin, thereby improving sleep. Individuals with very low levels of vitamin D are more likely to experience shorter sleep duration, lower sleep quality, and frequent awakenings during the night, according to a 2022 systematic review.

Overall, fish contains several nutrients that help your brain provide good, restorative sleep.

What can you do to increase the positive effects of fish on your sleep?

Plan a diet with greater food varieties rich in fish, fruits, and vegetables.

How do foods rich in tryptophan improve your sleep?

Tryptophan is an essential amino acid that serves as a building block for proteins. Your body uses it to make sleep-promoting chemicals like melatonin and serotonin.

Since your body cannot produce tryptophan on its own, it's essential to obtain it through your diet. Foods rich in tryptophan include whole grains, salmon, bananas, potatoes, legumes, eggs, and milk.

Tryptophan supplements can also help improve sleep quality, according to a 2022 systematic review. However, always consult your doctor before starting any supplements to ensure it's the right choice for you.

What can you do to increase the positive effects of tryptophan on your sleep?

Incorporate foods rich in tryptophan into your diet, such as whole grains, salmon, bananas, potatoes, legumes, eggs, and milk.

Putting it all together: ten dietary recommendations to improve your sleep

Now that we've explored how various foods and beverages can impact sleep, here are ten practical recommendations to help you tweak your diet for better sleep:

Plan a diet with greater food varieties rich in fibre, fruit, vegetables, and fish and low in sugar and saturated fat.
Incorporate foods rich in tryptophan into your diet, such as whole grains, salmon, bananas, potatoes, legumes, eggs, and milk.
Aim to have your dinner at least three hours before bedtime, allowing your body ample time to digest the meal.
Stop consuming caffeinated foods and beverages at least eight hours before bedtime.
Avoid consuming energy drinks and caffeine pills altogether.
Stop consuming alcohol at least three hours before bedtime.
Avoid using alcohol as a sleep aid.
Limit consumption of sugary foods and beverages, particularly in the evening.
Limit your intake of fast food and instant food products, as they are often high in unhealthy fats.
When preparing meals, use healthy alternatives instead of saturated fats.

Harness the power of your diet to transform your sleep

The interplay between your diet and sleep is a powerful one. While directly changing your sleep patterns may be out of reach, you have complete control over your dietary choices.

By consciously adopting a diet that promotes sleep, you can significantly improve your sleep duration and sleep quality. In turn, enjoying good, restorative sleep gives you the energy and motivation to maintain healthy dietary habits.

Sleep-disturbing dietary habits, on the other hand, can lead to poor sleep. In turn, poor sleep can lead to unhealthy dietary choices and increased cravings for high-calorie and less nutritious foods.

The relationship between diet and sleep is two-way; it can become a virtuous or vicious cycle. Either way, you're in control.

I encourage you to adopt a diet that supports your sleep. Start by closely observing your dietary habits to find areas for improvement. Then, focus on changing one habit at a time. Gradually, through consistent, sleep-promoting choices, you can help your brain rebalance your sleep/wake cycle, paving the way for the good, restorative sleep you deserve.