Sleep is not the same for everyone, and it should be viewed as individually as a person’s shoe size or height. Every human being has their own genetically determined chronotype (1). The chronotype indicates when their genetic sleep onset time and wake-up time occur. This can be determined via a hair root test (2), which identifies when the body begins the increased secretion of the sleep hormone melatonin. Only when this increased production takes place can one fall asleep after approximately 2 hours.
Sleep is not all the same
Depending on one's chronotype, the times during which one should consume food also vary. An extreme night owl with a genetically determined sleep window from 3:45 a.m. to 11:45 a.m., for example, has an eating window during which they can consume food without issue between 12:15 p.m. and 12:15 a.m. For a normal chronotype, who has a genetically determined sleep window between 11:30 p.m. and 7:30 a.m., this eating window lies between 8 a.m. and 8 p.m.
If we get up with an alarm clock, our body may not yet be prepared for food intake. So, if a normal chronotype is woken up by an alarm at 6 a.m., it does not mean they should eat breakfast right then, as their internal clock is not set for it until 8 a.m.
Although it is said that breakfast is the most important meal of the day and signals to the body that the day is beginning, there are also people who are not ready for their first meal until much later. It is important to develop a sense for your own body and listen to your hunger. Those who do not feel hungry in the morning are not yet adjusted to food intake and digestion. However, it is worth knowing that a lack of fluids in the body is often interpreted as a feeling of hunger. This refers to the kind of hunger that really makes your stomach growl.
Foods that can promote sleep
There are foods that are said to have a sleep-promoting effect. To understand this, one must know that the sleep hormone melatonin, which helps us fall asleep, is formed from the hormone serotonin. And the body creates serotonin from the amino acid L-tryptophan. Vitamin B1 and B6 as well as magnesium are also involved in the process of falling asleep. If we eat foods rich in these ingredients, we indirectly promote the production of melatonin and improve our sleep.
Vitamins B1 and B6, which are important for a normal energy metabolism and proper nervous system function, are essential for good sleep. Magnesium, which many people do not get enough of, also plays an important role in the falling-asleep process, as magnesium enhances the effect of GABA.
GABA is the neurotransmitter in the brain that inhibits neuronal stimuli that keep us awake and active. Through magnesium, these stimuli are conducted more slowly, which leads to our muscles and nerves relaxing. And this contributes to us being able to fall asleep better. Magnesium also has another function: it inhibits the secretion of stress hormones such as cortisol or adrenaline. This also helps us to fall asleep more easily.
Sleep and your mineral balance
For sleep problems, it is therefore advisable to have your vitamin and mineral balance checked by a doctor to see if there are any deficiencies, and then replenish them accordingly with supplements, as well as to integrate more foods into your diet that contain particularly high concentrations of these minerals and vitamins that can promote good sleep.
These include, for example, bananas, which have plenty of potassium, magnesium, L-tryptophan, and also many vitamins. High amounts of magnesium are found in sunflower seeds, pumpkin seeds, sesame, flaxseeds, as well as in avocados.
Those who would like to look into this further can search for foods with specific nutrients on the following page:
https://www.vitamindoctor.com/tools/naehrstofftabelle/
However, there are also foods that already contain melatonin. These include olives, pistachios, and mushrooms—the former in combination with magnesium, and the latter in combination with B vitamins. These can also be very well integrated into your diet to naturally support your sleep.
Sleep and your gut
A prerequisite for this, however, is that your gut is healthy and you have no problems. Our gut is responsible for ensuring that all these nutrients reach our bloodstream, and that only works if it is healthy. Furthermore, low stomach acid can also lead to nutrients not being fully filtered from the food by the gut and introduced into our system.
Other foods that can promote the falling-asleep process are so-called calming teas or valerian drops, which have a soothing and sleep-promoting effect. Ashwagandha is also a calming active ingredient that lowers the sympathetic nervous system, which leads to a decrease in cortisol levels. Since cortisol is the antagonist of melatonin, taking Ashwagandha as a dietary supplement in the evening can have a positive effect on sleep.
And a study in Great Britain has shown that a glass of sour cherry juice consumed by the participants in the morning and evening extended sleep duration and increased sleep efficiency (3).
Nutrition for shift work
With early and day shifts, one can adhere to their own eating times, which one should do if possible.
To avoid overstressing your body with food during the night shift, there are several things you can do to support it.
Warm meals
At night, you should only consume very light and preferably warm food, as the body is not adjusted for food intake at that time. In the natural rhythm, eating at night—during one's own sleep time—is not intended and is atypical. During this time, the body lowers its pulse, blood pressure, and body temperature. The production of digestive juices is also reduced. The body enters recovery mode. It is important to keep a few things in mind here, as the body generally lowers its pulse and blood pressure at night and produces fewer digestive juices in order to recover. If you eat anyway, it demands peak performance from the body.
No empty calories
Likewise, one should avoid so-called empty calories as much as possible. These are found, for example, in processed products, sweets, white flour products, chips, and cola. Instead, it is better to eat fruits and vegetables. A homemade vegetable soup with some whole-grain pasta, for example, is a good option for the night shift, or dishes with legumes and a few nuts or seeds.
Since fat burning is anything but running at full capacity due to the shift in natural rhythms, you should steam or boil vegetables rather than fry them in fat, and also avoid high-fat meals before the night shift.
Low points
Anyone who has to work regular night shifts also knows when their performance low point occurs. Once this time is known, you should eat something 2 hours before so that your blood sugar level does not drop to its lowest point. This could be, for example, a slice of whole-grain bread or whole-grain muesli.
Short movement breaks in the fresh air can also help.
It is particularly important, however, not to consume any caffeinated beverages at least four hours before the end of your shift that might help you get through the night better, because otherwise, the rude awakening in the form of insomnia will come when you get into bed in the morning.
Dos and don'ts in nutrition for good sleep
A central role in nutrition is played by an adequate intake of a wide range of vitamins and minerals, which support almost all types of bodily systems and processes. This also includes sleep.
There is now more and more evidence that an adequate intake of nutrients is important for sleep. A large study found that a deficiency in important nutrients such as calcium, magnesium, and vitamins A, C, D, E, and K is associated with sleep problems. Even if this research does not provide proof of cause and effect, it supports the likelihood that nutrition influences hormonal processes involved in sleep. In this respect, a balanced, preferably natural diet with plenty of vegetables and fruit, as well as eating at the right times, is a reasonable and recommended foundation for a healthy, good sleep.
Studies on the connection between diet and sleep have shown that a high intake of carbohydrates with a high glycemic index increases the number of nightly wake phases and decreases the number of deep sleep phases (4).
It is therefore by no means surprising that the frequent consumption of energy drinks and sugar-sweetened beverages is associated with poor sleep quality.
But there are indeed foods that can specifically promote or prevent good sleep.
Dos and Don'ts
Dos are, for example, the previously mentioned foods, teas, and supplements that, due to their ingredients, can specifically promote sleep or the secretion of melatonin, thus acting as sleep aids for humans.
Don'ts are foods that can prevent or worsen sleep in all people, partly because they suppress melatonin production, which is necessary for falling asleep, or signal to the body that it is not yet time to sleep.
This includes, among other things, caffeinated drinks like coffee, certain types of tea, and also the aforementioned energy drinks. Caffeine blocks adenosine receptors in the brain. However, adenosine is what makes us feel tired and calm. If you can still fall asleep despite caffeine in the evening, you have already developed such a high sleep deficit that the body falls asleep anyway due to the sleep pressure it feels. This is a very critical state that should be corrected as quickly as possible, allowing the body to get the restorative sleep it needs to perform its functions, which consist of repair work in the body and psychological regeneration. Lack of sleep makes you sick in the long run.
Hard to digest, hard to sleep
Another sleep killer is hard-to-digest food, which, if consumed too late, slows down the digestive process and contributes to making it harder to relax. Generally, you should eat your last meal at least 3.5 to even better 4 hours before bedtime, avoiding high-fat foods as well as vegetables such as cabbage, onions, leeks, and bell peppers. Meat and raw food in general also fall into this category. The digestive process for these foods generates heat. However, in order to enter the necessary resting mode, the body needs to lower its temperature slightly. In this respect, late consumption of hard-to-digest foods hinders the process of falling asleep.
Alcohol – First great, then bad
Another substance favored by many people because they feel nice and relaxed and tired after consuming it is alcohol. However, alcohol should be avoided because it makes us feel tired, but leads to very restless sleep.
After consumption, it quickly reaches the brain via the blood, acting there as a sedative on our nervous system and slowing down neuronal activity. That is also the dangerous thing about alcohol. We will leave aside the multitude of symptoms and long-term effects on our nervous system that alcohol consumption brings. Let's just examine its effect on sleep.
Most people know this: You have a glass of wine or beer in the evening, go to bed in a relaxed and tired state due to the alcohol, fall asleep, wake up after three to four hours, and then lie awake in bed. Falling back asleep then takes time, and usually, the sleep afterward is no longer restorative.
Strictly speaking, alcohol is a neurotoxin that has an enormous impact on our nervous system. However, since most people classify it as harmless and advertising ensures it is portrayed positively, it is the most consumed psychoactive substance that has a major negative impact on our sleep and our brain (5 and 6).
Sugar-sweet, but...
Let's move on to the last food item for today that can lead to sleep onset problems in humans - sugar! (7) Consuming sugary foods causes blood sugar levels to rise, which provides a boost of energy to the body and thus keeps us awake. So, definitely do not eat or drink anything sugary in the evening and avoid dessert, including ice cream, if you want to fall asleep better.
Conclusion
As you can see, there are many ways to support your sleep and sleep quality through diet alone. It is definitely worth trying out. However, you should also give yourself the necessary time to do so, because nutrition is not a pill that has an effect after a single use but does not usually remove the root cause. Good things take time - as an old proverb says. There is a lot of truth to that when it comes to nutrition. Try to eat a healthy diet for four weeks and enjoy the results.
Sources:
(1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8063933/)
(2 https://www.bodyclock.info/ )
(3 https://www.eurekalert.org/news-releases/736607)
(4 https://www.sleepfoundation.org/sleep-news/keto-diet-improves-sleep-quality)
(5 https://edition.cnn.com/2021/05/19/health/alcohol-brain-health-intl-scli-wellness/index.html )
( 6 https://www.ardurecoverycenter.com/alcohol-neurotoxicity/ )
( 7 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8848117/)
