A Complete Guide on the Connection Between Nutrition and Sleep

What Is Nutrition?

According to Harvard Health¹, nutrition is eating a regular balanced diet. The foods we consume supply our bodies with nutrients, which go into maintaining every aspect of our functioning: our brains, muscles, bones, nerves, skin, circulation, and immune system.

There are two types of nutrients: macronutrients and micronutrients. Essentially, macronutrients are carbs, protein, and fat. These serve as the building blocks for our muscles and tissues.

Micronutrients are individual vitamins and minerals, and they are important for maintaining a healthy immune system, among many other essential bodily functions. The combination of getting enough healthy macro and micronutrients equates to proper nutrition¹.

Conversely, malnutrition is the opposite of this. Usually, when we hear this word, our brains automatically go to starving groups of people who do not have access to food. While that accurately describes one type of malnutrition, the term actually encompasses anyone who is not getting proper nutrition, whether they are underweight or even overweight².

For example, a person who is not able to eat enough food may be malnourished and underweight, while a different person may be solely eating processed or fast foods and be equally malnourished but appear overweight.

Eating unhealthy foods can lead to all sorts of adverse health effects³, including a higher risk for obesity, cardiovascular problems, type 2 diabetes, cancer, and of course, sleep problems.

How Nutrition Affects Sleep

Eating foods that contain sugar, refined carbohydrates, and processed starches can negatively impact our sleep⁴ that very night. This is also true for drinking caffeine, even as far out as six hours⁵ before bedtime. Conversely, eating foods that are high in melatonin (for example, almonds, goji berries, eggs, fish, and tart cherries) can have an immediate positive impact on your sleep that night⁴ .

Nutrition also has a long-term, cumulative effect on sleep. If you’re consistently eating a diet that is low in nutrients (for example, a diet consisting mostly of fast food or processed foods), your body’s hormones will be adversely impacted⁴ . Hormones like the growth hormone, melatonin, cortisol, leptin, and ghrelin are directly correlated with sleep⁶ and your body’s natural circadian rhythm. When you mess with these hormones, it can lead to circadian rhythm sleep disorders.

Research also shows that not consistently not getting proper nutrition can increase inflammation in the body, which is closely related to insomnia and other sleep disturbances⁷ .

Can an Unhealthy Diet Impact or Cause Sleep Disorders?

Yes, an unhealthy diet can lead to certain sleep disorders. As mentioned earlier, a diet low in nutrients can impact your hormone levels across the board. Since hormones like the growth hormone, melatonin, cortisol, leptin, and ghrelin are responsible for keeping your circadian rhythm on track, altering the levels of these hormones can cause circadian rhythm sleep disorders⁸. These include delayed sleep phase disorder, which is when you may go to bed early into the morning and sleep in as late as 3:00 p.m., and advanced sleep phase disorder, which is when you may go to bed around 6:00 p.m. and wake up at 2:00 a.m.

Poor nutrition can also lead to a condition called obstructive sleep apnea⁹ (OSA). With this form of sleep apnea, oxygen levels in the blood drop rapidly due to an obstruction in the back of the throat. Usually, this is just caused by the relaxation of the throat muscles in deep sleep, but in people with OSA, the airways narrow too much, and they can’t get enough air. This lack of oxygen causes the body to wake up abruptly to breathe better.

Restless legs syndrome (RLS) is also impacted by diet. A research study¹⁰ found that participants who ate a diet rich in vegetables, fruits, nuts, soy, fiber, a healthy white-to-red meat ratio, polyunsaturated fats, and multivitamins were less likely to have RLS than those with a less healthy diet. Not coincidentally, incidents of RLS, OSA, and several other sleep disorders are much higher in people with obesity.

Research¹¹ also shows that it’s not just what we eat, but the way in which we eat that can lead to sleep disorders. For example, skipping meals throughout the day and then eating one large meal at night has been shown to increase the risk of sleep issues. Spicy foods, stimulants like caffeine or chocolate, eating things you’re intolerant to (like ice cream when you’re lactose intolerant), or even eating too quickly can have an immediate and direct impact on your sleep and lead to sleep disorders like insomnia¹¹ .

How Sleep Quality Affects Nutrition

Not only can the way you eat impact how well you sleep, but your sleep quality can also impact the way you eat. You may have already noticed that when you don’t get enough sleep one night, you’re much more likely the next day to crave carbs and sweets. On a scientific level, this makes sense; you’re running low on energy due to a lack of sleep, so your body craves the foods that will give you the fastest source of energy¹². For more information, check out our article on the connection between obesity and sleep.

On top of this, not getting enough sleep causes the body to produce too much ghrelin¹³ (a hormone that stimulates appetite) and too little leptin (the hormone that tells us we are full).

Finally, research also shows us that sleep deprivation – both short-term and long-term – has a direct impact on our decision-making abilities¹⁴, which means you may be more inclined to make poor food choices.

All of these combined factors lead to craving more high-calorie and carb-heavy foods, an inability to feel as full as we ought to, and a decreased ability to make good decisions about what we’re eating. This can happen after just one or two nights of sleep deprivation; if you’re consistently not getting enough sleep, this may mean a lifestyle of poor eating.

Tips to Improve Your Nutrition for Better Sleep

• Don’t consume sweets, foods high in fat, caffeine, or alcohol before bed – All of these foods and drinks can either keep you up late, or disrupt your sleep¹⁵ through the night.
• Avoid spicy foods at night – Spicy foods tend to cause or exacerbate acid reflux¹⁶. When you lie down to sleep, the spicy foods and your position may make heartburn worse. Spicy foods have also been shown to make sleep apnea worse16.

Learn more: How to Sleep Better with GERD and Acid Reflux

• Avoid processed cheese, salami, or pepperoni at night – These processed foods contain tyramine, which can release norepinephrine16. This can make your brain overactive and excited – not a good thing for a good night’s sleep.
• Don’t eat dinner too early or too late – Experts say that the ideal time to eat dinner is about three hours before bed. This means you’ll have time to digest your food, but you also shouldn’t feel hungry when you lie down to sleep. Going to bed hungry can also have a negative impact on sleep¹⁵.

Find out more: Should You Eat Before Bed?

• If you must snack late, snack correctly – If you’re starving before bed, you’re probably not going to be able to sleep. Late-night snacks should be small, simple, and easy to digest. Something like whole wheat toast with almond butter, Greek yogurt with berries, or a small bowl of high-fiber oatmeal should not be too activating or hard to digest at night.
• Eat foods high in fiber and low in saturated fat and sugar – Research¹⁷ shows that eating a high-fiber, low-saturated fat, and low-sugar diet leads to deeper, more restorative sleep.
• Consume foods that foster better sleep – Aside from foods high in fiber and low in saturated fat, there are particular foods that promote better sleep. Kiwis, cherries, and walnuts, for example, are rich in melatonin and magnesium, which are good for sleep. Fatty fish like salmon is also great for sleep¹⁸, as it helps regulate serotonin levels.

Read more about the best foods for getting a good night’s sleep

• Drink something warm (and caffeine-free) at night – Drinking something warm like chamomile tea before bed can help you wind down after a long day. Be sure your warm drink is free of sugar and caffeine, though, to sleep well.
• Try adding magnesium before bed – Eating magnesium-rich foods or even adding magnesium supplements before bedtime could be a game changer for sleep. Magnesium¹⁹ has been found to be an effective, natural sleep aid.