That nutrition plays a central role in our health is no secret. After all, the old adage “you are what you eat” acknowledges how important nutrition is for our well-being. This concept is taking on an added dimension as research demonstrates the impact of diet on sleep.
It is estimated that nearly one-third of Americans suffer from insomnia and related sleeping problems. Dietary problems are also abundant with an obesity rate in America hovering near 40%.
Researchers studying both of these public health problems have noted a strong link between sleep and obesity, and there is strong reason to believe that improving diet can improve sleep and vice versa.
In this guide, you can find more information about this relationship between dieting and sleep. We’ll discuss specific diets, review foods that can help and hinder sleep, and answer many frequently asked questions about nutrition and sleep.
Does Food and Nutrition Affect Sleep?
Food and nutrition can have a profound impact on sleep. A healthy diet and eating habits can promote both higher quality sleep and more total sleep time.
Studies have long recognized that there are connections between poor sleep and poor diet. People with various type of sleep disturbances have a tendency to also have inconsistent or unhealthy diets. However, in many of these studies, it can be hard to tell the direction of causality. As it turns out, it is likely that sleep affects nutrition and that nutrition affects sleep.
How your body processes food and nutrients depends on what, when, and how much you eat. Eating instigates a series of reactions in the body, and the nature of those reactions can influence your ability to fall asleep as well as your sleep architecture. At the same time, getting poor sleep has been associated with obesity and can be associated with poor dietary choices.
The way that individuals respond to food is extremely variable and can depend on a person’s genetics, environment, stress, activity, gut microbiome, and other factors. Researchers are just beginning to deepen their understanding of these complex and interrelated systems. As a result, it can be challenging to state exactly how a diet or food will impact a specific individual, but at a general level, it is clear that how we eat can directly influence how we sleep.
How Do Diets Affect Sleep?
Everyone has a diet; diet simply refers to what you eat. But when people are “on a diet” or follow a specific diet, it means that they adhere to a certain set of rules about what foods to eat.
Our food intake and how our body processes it can impact our sleep, so different types of diets that restrict particular foods or nutrients can have varying effects on sleep.
In this section, we’ll describe some common diets and their potential effects on sleep. However, keep in mind that many bodily systems are involved in regulating metabolism and processing food. Every person is unique, and the same food or diet can affect people in markedly different ways. A doctor or nutritionist is in the best position to offer personalized advice about the optimal diet for any individual.
A vegan diet avoids any product derived from animals including meats but also dairy products like cheese, milk, and eggs. Because of the considerable restriction involved in a vegan diet, it is common for vegans to carefully plan their meals, and this can help avoid some of the negative impacts to sleep that can come from overeating or splurging on extremely fatty or sugary dishes.
No detailed study has documented the effects of a vegan diet on sleep, but many vegan diets include complex carbohydrates, nuts, and fruits that contain tryptophan and melatonin that can promote good sleep. A vegan diet frequently avoids some foods that can disrupt sleep such as heavy meat-based dishes.
Transitioning to a vegan diet is sometimes reported to cause sleep problems. This may be part of an adjustment period or can reflect a change in nutrient intake, such as a drop in protein or overall calories, that may make it harder to initiate sleep.
Vegetarians do not eat meat products of any kind but still consume other products, like eggs and dairy, that are derived from animals. Like with vegans, the extra planning that may be required to eat a vegetarian diet can help add consistency to a person’s diet that can make it easier for the body to process food without disruption.
Vegetarian diets frequently feature similar foods to those of the vegan diet that can promote sleep including almonds, fruits, and whole grains. The addition of milk and yogurt can add melatonin as well. Like vegans, vegetarians may avoid sleep problems that can come from excess meat consumption.
A pescatarian diet excludes all meat products except for fish and seafood. Pescatarians can still eat other animal products like eggs and dairy but frequently rely on fish for the bulk of their protein.
Many types of fish have omega-3 fatty acids and vitamin D that may help in regulating serotonin and promoting sleep.
Though the research is still limited, there is some indication that eating fish has positive benefits overall for sleep.
In avoiding red meats, many pescatarians, like vegetarians, include items like yogurt, nuts, and fruits that can offer useful nutrients for getting quality sleep.
Keto refers to the ketogenic diet that is based around dramatically reducing the body’s net carbohydrate intake in order to put the body into ketosis. Ketosis is the state in which the body uses stored fat, rather than carbohydrates, for its energy needs.
Ketogenic diets have recently grown in popularity but still require considerable research to fully understand their benefits and risks. Some people describe “keto insomnia” or having difficulty sleeping when first beginning this diet.
This may be related to the body’s overall process of adjusting to being in ketosis. Keto diets are frequently heavy in meat consumption, which, as mentioned above, may have negative impacts on sleep. However, one study of the ketogenic diet in obese patients found no impact on sleep quality.
Keto is not the only type of low-carb diet. Other diets, such as the Atkins diet, are also based on restricting carbohydrates. Research about low carbohydrate diets and sleep have had mixed results. High carbohydrate diets promote falling asleep more quickly, but these diets may reduce sleep quality or alter sleep architecture. This may also depend on the type of carbohydrate and the time it is consumed.
The Paleo diet, also known sometimes as the caveman diet, is restricted to the types of foods that would have been available to early humans whose food was obtained through hunting and gathering. This diet excludes refined sugars, dairy, agricultural products like wheat, and other processed foods.
Some people on the Paleo diet say their sleep improves while others have insomnia, especially at the beginning. One small study found that people reported sleeping problems on the Paleo diet. The diet includes nuts and fruits that include melatonin but commonly involves lots of meat that may have detrimental effects on sleep.
Raw Food Diet
The raw food diet involves eating only or predominantly uncooked foods, typically fruits, vegetables, and nuts. There is no concrete data from controlled research studies about raw food diets and sleep, and individual experience vary considerably from those with difficulty sleeping to those who find their sleep improved.
The significant amount of fruits and vegetables may help increase sleep-promoting nutrients, but at the same time, other important nutrients can be difficult to get on a raw food diet. Avoiding fatty meats and other heavy dishes may reduce sleep disruptions.
As with other highly restrictive diets, the raw food diet requires significant planning and attention-to-detail, and this can add consistency and avoid dietary peaks and valleys that may interfere with sleep.
Foods That Will Help You Sleep
Our diet is made up of many individual foods, and that overall diet is what’s most important for promoting overall health. That said, certain specific foods may be able to help you sleep well throughout the night.
Tart Cherries - Tart cherries include several specificcultivars of cherries, such as Richmond, Montmorency, and English Morello, that are distinct from sweeter types of cherries. These cherries have higher concentrations of melatonin and may be useful in promoting sleep. Pure tart cherry juice -- not mixed cherry juice or cocktail juice -- is a common way for these to be consumed.
Kiwi Fruit - Kiwis, the small, round fruits commonly associated with New Zealand, have been found in some small studies to promote sleep when eaten about an hour before bedtime. The exact mechanism is unknown, but it may be related to the content of antioxidants, folate, and serotonin found in the kiwi fruit.
Malted Milk - Malted milk is commonly associated with James Horlick, who is widely acknowledged as its initial inventor and promoter. His recipe involved milk, malted barley, wheat, sugar, and an assortment of vitamins and minerals. Studies have found it can improve sleep, and it is believed that this may be related to the vitamins, such as vitamin D. Natural melatonin-enriched milk is another milk product that may offer benefits before bed.
Oatmeal - A bowl of oatmeal before bed may be useful in getting better sleep. Oats contain tryptophan, an amino acid that is related to sleep because of how it can increase levels of serotonin and melatonin. At the same time, oatmeal has carbohydrates that may help tryptophan reach the brain.
Almonds and Walnuts - Almonds and walnuts are handy snacks that may help to promote sleep because of their melatonin content. These nuts have healthy fats and do not require any advance preparation to have ready to eat before bedtime. They may also be combined with other pre-bed foods like oatmeal.
Foods to Avoid Before Bed
Certain foods may make it harder to get to sleep or can disrupt your sleep architecture. If you are thinking about nutrition and sleep, these are foods to avoid before bedtime.
Chocolate - Though chocolate tastes great, it contains caffeine that can make it harder to get to sleep and to stay asleep throughout the night. Because the caffeine comes from cacao, the concentration of caffeine will be higher in dark chocolate than in milk chocolate. The addition of sugar to chocolate may combine with caffeine to further harm sleep
Hot Sauce - Most experts recommend against eating any kinds of spicy foods, including things seasoned with hot sauce, before bed. Research studies have shown that doing so can have a negative effect on sleep because of the possibility of indigestion and because spicy foods can raise body temperature during the first sleep cycles of the night.
Fried Foods - Fried foods are by nature fattier and heavier, and the challenge of digesting them while trying to go to bed can be disruptive of sleep. Fried foods can also promote reflux that disrupts sleep. In addition, many fried foods are also meats, and as we outlined previously, heavy meat consumption may have negative effects on sleep.
Candy - Most candies have high concentrations of sugar and consuming that sugar causes the pancreas to produce insulin to help control your blood sugar. Unfortunately, those spikes of blood sugar and insulin before bed may be disruptive of your ability to get a good night’s sleep.
Alcohol - A nightcap before bed might make you feel sleepy, but overall it has a detrimental effect on your sleep. Research has shown that alcohol interrupts sleep architecture and can make it more likely that you will wake up during the night. In addition, drinking too much can cause hangovers and significant daytime sleepiness the next day.
Frequently Asked Questions About Diet and Sleep
Both nutrition and sleep are huge topics, so it’s common to have questions about making the most of your diet and sleep. In this section, we’ll cover some of the frequently asked questions about food and sleep.
Does intermittent fasting affect sleep?
Evidence to date is limited but has not shown any clear positive or negative impact of intermittent fasting on sleep.
Intermittent fasting is an approach to dieting that focuses on regular periods with no food intake. Some approaches to intermittent fasting involve only eating during an 8-10 hour period each day, creating daily 14-16 hour fasts. Other ways of doing intermittent fasting may involve fasting for one full day for every few days without fasting.
It is believed that intermittent fasting may promote a healthy circadian rhythm. There is no clear data about intermittent fasting in large part because this is a relatively recent dietary approach and because there are various ways of implementing a diet based around intermittent fasting.
Intermittent fasting may affect hunger levels, especially when first becoming accustomed to this pattern of eating. This may influence sleep onset as some people struggle to fall asleep when hungry. However, studies of people during Ramadan, a religious holiday that involves on eating after sundown, have found no major negative consequences on sleep.
Do you burn fat while sleeping?
Our bodies burn calories during sleep and while we’re awake. Many people assume that we’re burning more calories during waking hours, but sleep deprivation can affect metabolism in ways that actually decrease calorie burning overall. In a study supported by the U.S. National Institutes of Health (NIH), people who slept 8.5 hours per night burned more calories and lost more weight than people on the same diet who slept only 5.5 hours per night.
Sleeping less seems to promote appetite and increases the likelihood that we eat too much. Lack of sleep can also affect mood and may make us more prone to emotional eating.
In this way, we not only burn calories and fat while sleeping but getting good sleep helps prime the body for fat reduction and weight loss overall.
Does sleeping well help with weight loss?
Yes, getting plenty of sleep is an important part of any weight loss plan. As we described in the prior answer, studies have shown that people following the same calorie-restricted diet had much worse results -- a 55% reduction in weight lost -- when only sleeping 5.5 hours a night relative to others who slept 8.5 hours.
Sleep is critical to so many of our bodily systems for wellness, and its role in promoting healthy metabolism and weight is one clear example.
What foods help babies sleep?
There is no food that can assure that a baby will sleep, let alone sleep through the night. A feeding shortly before an infant goes to bed -- but not actually in bed -- can be a helpful part of their routine.
When possible, transitioning a baby to solid foods may have positive impacts on their sleep. In a study conducted in the UK, babies fed with solid food along with breast milk starting at 3 months slept longer and had fewer instances of crying and irritability.
That said, some organizations recommend not introducing solid foods until later because in some cases they may be harder for babies to digest. Parents are encouraged to talk with their child’s doctor with any questions about the optimal diet for their age.
Can food allergies cause sleep problems?
Some food allergies may cause sleeping problems because of the impacts that they can have on the body. For example, food intolerances and allergies cause indigestion, nausea, or diarrhea that can be discomforting and can interrupt a night’s sleep. For example, research has found higher rates of sleep disturbances in people with an allergy to gluten (known as Celiac disease). Food allergies may also cause sleep disruptions because they can overstimulate the nervous system.
Does spicy food affect sleep?
Yes, spicy food eaten too soon before bedtime can disrupt sleep. As we described in the section on foods to avoid before bed, spicy food can cause indigestion and cause raise your body temperature in a way that disturbs your typical sleep cycles.
What is the best time to eat?
In general, it is best to eat dinner at least a few hours before bedtime and to limit snacking in the lead-up to bed. Setting a clear routine can have benefits as part of overall sleep hygiene.
Research indicates that food intake before bed seems to have negative consequences for sleep quality. This impact appears to be more pronounced for people who eat before bed only rarely rather than as a matter of habit. The adverse effect on sleep architecture of eating 30-60 minutes before bedtime was also greater in women than in men.
Instead of eating before bedtime, it may be more useful to consider drinking a sleepytime tea as part of the routine of getting prepared to go to sleep.
What is the sleeping beauty diet?
The sleeping beauty diet attempts to address hunger not with eating but with sleeping, adhering to the idea that time spent sleeping is time not spent taking in calories. In order to accomplish this, many followers of this diet use sleep aids or painkillers to sleep for as many as 20 hours per day.
The sleeping beauty diet is not supported by science and is not recommended. It can lead to daytime fatigue and disordered eating that may be unhealthy and contrary to the goal of weight loss. It frequently is not convenient to sleep when hunger arises, and using medications or drugs to sleep can lead to addiction and the need to constantly ramp up their use in order to achieve the same result.
On the whole, the sleeping beauty diet has no basis in nutrition research and has major potential negative consequences in both the short and long term.