Can Your Diet Affect Your Sleep?

About 70 million people in the United States struggle with at least one sleep disorder. Several studies have shown that sleep duration and quality are associated with the risk of obesity or weight gain, diabetes, hypertension, and cardiovascular disease.

We know that blood sugar can affect sleep and that nutrition has a big impact on glucose levels. But many people haven’t considered the way diet may impact sleep.

So, what dietary factors may be responsible for disrupting your good night’s sleep? Read on to learn more about how your diet may affect your sleep patterns. 

Sleep and Food: Is There a Connection?

The link between nutrition and many of the top health concerns in today’s world is well-known. And as it turns out, your food choices, meal timing, and nutrient balance might actually influence how well you sleep.

The effects of diet and sleep can be a two-way street when it comes to your well-being. It’s not only our food choices that affect how we sleep —  how we sleep can affect our food choices as well. Because studies have identified a relationship between sleep duration and obesity, there has been much interest in assessing the impact of sleep on energy intake.

Energy intake is the total balance of all the energy you consume from food. This energy comes from the carbohydrates, fat, protein, and alcohol you consume. 

Research has shown that people who don’t get enough sleep tend to have higher energy intakes from snacks and fat. Not getting enough variety and essential nutrients in your diet can have negative consequences on your health. During periods of sleep restriction, people also tend to snack more.

Understanding Sleep Problems

Sleep is crucial for good mental and physical health. Ideally, healthy adults should be getting no less than about seven to seven and a half hours of sleep per night. 

Sleep deprivation has been linked to negative health outcomes. For example, if you don’t get enough sleep, your risk for conditions including hypertension, obesity, type 2 diabetes, and cardiovascular disease may increase.

Other research suggests that lack of sleep can lead to mood disorders and neurodegenerative disorders like dementia. Lack of adequate sleep also affects your psychological well being: it can impact our moods and exacerbate stress.

Sleep disorders are problems that can disrupt and change the way you sleep. These disorders, which include insomnia, obstructive sleep apnea, narcolepsy, and more, can have a significant effect on your wellbeing. Other conditions such as heartburn or acid reflux can also lead to difficulty sleeping.

Some common symptoms of sleep disorders include:

• Being sleepy during the daytime
• Trouble falling asleep at night
• Falling asleep at inappropriate times, like while driving
• Breathing in an unusual pattern during sleep
• Feeling an uncomfortable urge to move while you are falling asleep
• Unusual or bothersome movements or experiences during sleep
• Having an irregular sleep and wake cycle

If you experience any of these symptoms or are worried you may have a sleep disorder, visit your doctor or medical provider.

What is a Regular Sleep Cycle?

Healthy sleep follows a regular sleep cycle that includes two phases: rapid eye movement (or REM) and non-rapid eye movement (NREM) sleep. NREM sleep is further divided into three stages: N1, N2, and N3. 

Ideally, your body will cycle through all of these stages four to six times per night, with each cycle lasting roughly 90 to 110 minutes. During each stage, your brain wave patterns, muscle tone, and eye movements change. Here are the four stages of a regular sleep cycle:

N1: The First Stage of Sleep

The first phase of the sleep cycle is the NREM phase. Approximately 75 percent of sleep is spent in this phase. 

The first stage of sleep is the N1 stage, or Stage 1. This is a very light sleep that lasts only about 1 to 5 minutes, making up only five percent of total sleep time. During N1, your breathing and muscle tone are regular and your brain waves begin to change. 

N2: The Second Stage of Sleep

The second stage is N2, or Stage 2. This is a deeper sleep than N1, and lasts about 25 minutes during the first cycle, lengthening with each successive cycle. This deep sleep phase makes up about 45 percent of total sleep time. 

During N2, your heart rate and body temperature drop, and neurons begin firing in the brain. These neurons are associated with memory consolidation, which is when your experiences are transformed into long-term memory. This is also usually the stage when teeth grinding occurs. 

N3: The Third Stage of Sleep

The third stage of NREM sleep is N3, or stage three. This is the deepest NREM sleep, and makes up about 25 percent of total sleep time. It is also called SWS, or slow wave sleep. 

During N3, your body repairs and regrows tissues, builds bone and muscle, and strengthens the immune system. This is also usually the stage when night terrors, sleepwalking, and bedwetting occurs. 

It is difficult to wake from N3 sleep, and studies show that people awakened during N3 have a phase of mental fogginess or impaired cognitive performance for 30 minutes to an hour.

REM Sleep

Rapid-eye movement sleep is the second phase of the sleep cycle and makes up about 25 percent of total sleep time. This phase usually starts 90 minutes after you fall asleep, and your REM cycles get longer throughout the night. 

Your brain, eyes, and diaphragmatic breathing muscles stay active during this phase, but your skeletal muscles don’t move. REM is when dreaming occurs. If you awaken spontaneously in the morning, chances are you awoke from the REM phase. 

Sleep that contains 4-6 full cycles of NREM and REM sleep is considered to be more restful and restorative. 

What Does the Research Say About Diet and Sleep?

It’s not always easy to study the many complex ways our food choices may impact your overall sleep. Sleep itself is directed by many different hormones, neurotransmitters, and cell signaling systems.

Your unique health history and genes can also come into play. Because everyone is different with unique dietary and health needs, working with a qualified dietitian professional may be beneficial in determining how your unique diet plays a role in how you sleep. 

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Factors that May Negatively Impact Sleep

Different compounds found in our foods, including vitamins, minerals, phytochemicals, and other bioactive compounds, may impact the systems that control sleep in a variety of ways depending on what, when, and how much we eat. 

For example, one epidemiological study of middle-aged female Japanese workers and their dietary habits found that a high intake of candy, sweets, and noodles was associated with poor sleep quality. 

The study also found a significant trend toward worse sleep quality with increasing carb intake. Conversely, a high intake of fish and vegetables was associated with good sleep quality. 

Frequent consumption of energy drinks and sugar-sweetened beverages was associated with poor sleep quality. Skipping breakfast and eating irregularly were also strongly associated with worse sleep quality.

These findings suggest that the timing and regularity of meals is also important when it comes to sleep. However, although there does appear to be a relationship between sleep quality and dietary patterns, some of the studies noted above stated that it was unclear whether the subjects’ sleep was affecting their diet, or vice versa. 

Vitamins and nutrients may also have an effect on sleep quality. Deficiencies in vitamin B1, folate, phosphorus, magnesium, iron, and zinc have been associated with shorter sleep duration. Low selenium, calcium, vitamin D, vitamin C, and lycopene were also connected to poor sleep quality and maintenance.

Alcohol has been found to reduce REM sleep and cause sleep disruptions. Other research has also shown that caffeine may interfere with circadian melatonin rhythms and may block the sleep-promoting effect of adenosine.

More About Carbs and Sleep

Both high carbohydrate and low carbohydrate diets are associated with changes in sleep. According to research, a low-carb diet seems to reduce REM sleep and increase slow wave sleep, while a high-carb diet may have the opposite effect. 

Studies show that people with insomnia symptoms are more likely to have a low carbohydrate intake, but those same people are shown to have a high intake of sweets. This could mean that the quality of carbohydrates is important to sleep quality. 

Some research has shown that a high-quality carbohydrate meal at dinner may make falling asleep easier and reduce wake time during the night, while a low carb diet causes significant sleep disruptions and difficulty maintaining sleep. However, longer-term effects have not been examined in randomized controlled studies.

Dietary Fat and Sleep

Research shows that the fat content of your food may also influence REM and slow wave sleep. This effect may be mediated through the postprandial release of cholecystokinin, a satiety hormone released by the gut after a high fat meal and may improve some aspects of sleep.

In other studies, low-fiber, high-saturated fat, and high-sugar intake was associated with lighter, less restorative sleep with more waking up during the night. More research is needed on this connection, as longer-term effects have not been examined in randomized controlled studies.

It’s important to remember that in exploring your unique sleep and diet concerns, you should consult with your qualified primary medical provider or dietitian to consider your individual health needs. 

Can Certain Foods Improve Sleep?

Is it true that specific foods can improve your sleep? Foods like milk, fatty fish, cherries, and kiwi are commonly studied for their impact on sleep because of their melatonin, tryptophan, or vitamin and mineral content. However, despite some anecdotal evidence, scientific research on the effects of these foods on sleep is limited. 

However, studies have shown that European women who adhere to a Mediterranean diet tend to have better sleep quality. The Mediterranean diet is composed of nutrient-dense fruits and vegetables, legumes, unsaturated fat, and plant-based proteins. 

This research suggests that a high intake of fish and seafood paired with nutrient-rich fruits and vegetables may benefit sleep. Adequate vitamins, minerals, protein, and electrolytes also appear to be important for sleep quality, especially in older adults. This healthy eating pattern also has the benefit of positively affecting your blood glucose, which may also impact your sleep. 

Increasing zinc-rich foods in particular has been shown to improve the ability to fall asleep and get better sleep. Meat, poultry, and seafood are all good sources of zinc. 

However, clinical trials that examine the influence of these foods and related nutrients on sleep are limited by small study populations and short interventions. Therefore, more research is needed to determine if incorporating specific foods into your diet may improve your sleep.