6 Foods That Keep You Awake at Night

1. Caffeinated foods and beverages

When you think of foods and drinks that give you immediate energy, coffee and other caffeinated products may come to mind.

This is because caffeine is a central nervous system stimulant, meaning it increases feelings of alertness and makes you feel more awake and energized (2).

Because of this effect, caffeinated foods and beverages, including soda, coffee, caffeinated tea, and caffeinated chocolate products may negatively affect sleep and keep you awake at night.

In fact, research shows that consuming coffee, even many hours before bedtime, can affect sleep. A small 2013 study in 12 people found that consuming 400 mg of caffeine at bedtime, as well as 3 and 6 hours before bed, significantly disrupted sleep.

Interestingly, ingesting 400 mg of caffeine 6 hours before bed more than doubled the time it took for participants to fall asleep and reduced total sleep time by 1 hour, compared with a placebo (3).

This lack of sleep due to caffeine consumption may lead you to drink a lot of caffeine the next day to counteract feelings of tiredness, which can negatively affect the next night’s sleep. Some people refer to this cycle as the coffee cycle (4).

While some people are very sensitive to caffeine and experience sleep-related issues even if they consume a small amount, others can have caffeinated beverages closer to bedtime without experiencing sleep issues. This is due to genetic variations (5, 6).

So, even though experts recommend cutting back on caffeine to promote restful sleep, it’s especially important if you’re sensitive to caffeine.

Foods that contain caffeine include:

• chocolate
• coffee, including decaf, though in lower amounts than regular
• foods that contain kola nut as an ingredient
• green and black teas
• guarana
• yerba mate
• energy drinks
• foods that contain caffeine or coffee as an ingredient, such as tiramisu

What if you want to stay awake?

If you’re using caffeine to stay awake, say for a night shift, it might not be the best plan. Studies show that using caffeine to stay awake for night shifts and to shift sleep to the following day may lead to significantly decreased sleep quality overall.

In a 2006 study in 34 people, half of the participants followed a standard sleep routine of sleeping at night, while the other half stayed up at night and slept during the day. Both groups ingested 200 mg of caffeine before bedtime.

Both groups experienced sleep disturbances, including difficulty falling asleep, compared with those who took a placebo.

However, caffeine more negatively affected the participants who slept during the day. Only this group experienced decreased sleep duration and decreased deep REM sleep after consuming caffeine (7).

A 2018 study in nighttime shift workers found that those who consumed more caffeine had greater sleep disturbances and psychological distress (8).

Thus, even though caffeine may give you a temporary boost of energy, it may keep you from getting restful sleep.

Summary

Caffeine is a central nervous system stimulant and may negatively affect sleep, especially if you consume it within 6 hours of bedtime. It may give you a temporary boost of energy, but ultimately have a negative impact on sleep duration and quality.

2. Spicy foods

Eating spicy foods close to bedtime may keep you awake for several reasons.

Spicy foods are known to cause indigestion and worsen symptoms of heartburn and acid reflux (9, 10, 11).

When you lie down to go to sleep, these spicy food-related symptoms can become worse, as acid may travel into the esophagus, causing irritation. This can keep you awake at night and lead to sleep disturbances (9).

Therefore, if you experience heartburn after eating spicy foods or you have acid reflux, you may want to steer clear of spicy foods before bed.

Eating very spicy foods, like chili peppers, slightly increases your core and surface body temperature (12).

This effect is temporary. However, some researchers have proposed that an increase in body temperature from eating spicy foods before bed may negatively affect sleep. Elevated body temperature is linked to sleep disturbance (9).

Summary

Spicy foods may lead to indigestion and reflux symptoms, which may disturb your sleep. Eating spicy foods before bed may lead you to feel warm, which can negatively affect sleep.

3. High glycemic index foods and added sugar  

Foods that have a high glycemic index (GI) rapidly increase blood sugar levels. These foods include refined carbs like white bread, sweets, and foods with high amounts of added sugars.

That said, research on the effects of high GI foods on sleep shows mixed results. Some studies link high GI diets with insomnia and sleeping issues, while others suggest a high GI meal decreases the amount of time it takes people to fall asleep (13, 14).

A 2019 study that included data on more than 77,000 women found that those who followed a high glycemic diet were more likely to have insomnia over a 3-year follow-up period.

The study also found that consuming added sugar and refined carbs was associated with higher odds of insomnia (15).

Other studies have shown that diets high in sweets, sugar-sweetened beverages, and refined carbs were associated with poor sleep quality (16, 17).

A 2016 study that included data on 18,779 adults found that people who slept 5 hours per night or less had a 21% higher intake of sugar-sweetened caffeinated beverages, compared with those who slept 7 hours per night or more (18).

It’s important to note that this study was observational. So, it only shows there was an association, but it can’t say for certain what caused people to lose sleep.

In addition, the people in this study may have slept less due to the caffeine in the beverages, not just the sugar.

There are several reasons why a high glycemic diet and foods high in added sugar and refined grains seem to be associated with poor quality sleep.

High GI foods cause significant spikes and drops in blood sugar levels. This triggers your body to release hormones, like adrenaline, cortisol, and growth hormone, which can lead to symptoms like anxiety, hunger, and irritability.

Studies show that low blood sugar may reduce sleep efficiency. On the other hand, high blood sugar after a high glycemic meal may initially make you feel sleepy, but the resulting changes in hormones, including insulin, may cause you to wake up later in the night (15).

High glycemic diets also trigger inflammatory responses in the body and create imbalances in beneficial intestinal bacteria, which may also affect sleep (15).

Summary

High glycemic diets and diets rich in added sugars may negatively affect sleep. Consuming foods high in added sugar close to bedtime may lead to insomnia and difficulty staying asleep.

4. Fatty foods 

Eating foods high in fat, like fried chicken and fatty meats, may contribute to poor sleep.

Research shows that greater fat intake, especially saturated fat, may negatively affect your sleep pattern.

A 2016 study in 26 adults found that a higher intake of saturated fat was associated with lighter, less restorative sleep (19).

Another study that included 459 women found that the more total fat and saturated fat participants consumed, the lower their total sleep time (20).

A 2015 study in 211 men demonstrated that men who had insomnia had a higher intake of saturated fat than men who didn’t have sleep disorders (21).

Additionally, a 2016 study that analyzed data on 15,273 men found that men with insomnia had diets higher in trans fats than men without insomnia (22).

Additionally, having a heavy, fatty meal later at night may affect your ability to fall asleep.

This may be because your digestive tract slows when you’re sleeping, so eating a fatty meal may overwhelm the digestive system, leading to discomfort that can keep you awake at night (23).

Furthermore, high fat foods are known to exacerbate symptoms of acid reflux, which may keep you awake at night (24).

Summary

Diets high in total, saturated, and trans fats may lead to sleep disturbances and keep you awake at night.

5. Fast food and other ultra-processed foods

Ultra-processed foods like fast food and packaged snacks may not be the best choice for restful sleep.

Research consistently links diets high in ultra-processed foods to poor sleep quality and short sleep duration.

A 2018 study that included data on 118,462 adolescents aged 12–18 discovered that shorter sleep duration and poor sleep quality was associated with higher intakes of fast food, instant noodles, and sweets (16).

A 2020 study investigating the sleep habits of Brazilian adolescents linked poor sleep quality to a higher intake of ultra-processed foods (25).

No available studies looked at the effects of ultra-processed foods on sleep in adults specifically.

The results of the 2020 study aren’t surprising, considering the nutritional composition of ultra-processed foods. These foods tend to be high in ingredients linked to sleep disturbances, including refined carbs, added sugar, and saturated and trans fats (25).

What’s more, diets high in ultra-processed foods can lead to weight gain. Studies show that people with overweight or obesity tend to have more sleep issues than people without (26, 27, 28, 29, 30, 31).

Obesity may lead to obstructive sleep apnea, a health condition that can make it hard to breathe at night, resulting in sleep loss (28, 31).

Summary

Studies have found links between ultra-processed foods and poor sleep quality. Cutting back on ultra-processed foods is beneficial for overall health and may help you get a better night’s sleep.

6. Alcoholic drinks

Many people like to have a drink or two at night to relax and unwind before bedtime. In fact, alcohol is one of the most commonly used sleep aids (32).

Even though having a few drinks may initially make you feel tired, studies show that drinking can cause sleep disturbances and keep you awake at night (33).

Interestingly, alcohol causes you to fall asleep faster, but then significantly disrupts sleep during the night as your blood alcohol levels decline (34).

A 2020 study in 11,905 people found that higher alcohol consumption was significantly linked to poorer sleep and shorter sleep duration (35).

A 2019 study in 25 people found that consuming a large amount of alcohol significantly reduced total sleeping time and self-reported sleep quality (36).

Because alcohol is so strongly linked to insomnia, healthcare professionals usually recommend avoiding alcohol before bed as part of insomnia treatment (37).

If you regularly drink alcohol before bed to relax or as a way to fall asleep, it’s important to understand that, although alcohol will likely make you tired at first, it will negatively affect your overall sleep quality and may keep you awake later in the night.

Summary

Alcohol reduces the time it takes to fall asleep, but it leads to sleep disturbances later in the night. To promote restful sleep, it’s best to avoid drinking alcohol before bed.

The bottom line

If you have difficulty falling or staying asleep, avoiding certain foods and beverages may help.

Studies have linked caffeinated foods and beverages, added sugar, refined carbs, spicy foods, high fat foods, and alcohol to poor sleep quality and shorter sleep duration.

To promote restful sleep and minimize the chances of waking up at night, consider limiting or avoiding the foods and beverages on this list, especially later in the day and before bedtime.

Food Fix: Better Sleep