Sleep and nutrition are closely linked. What you eat, when you eat and even what nutritional supplements you take can all play a role in how well you sleep. Much of what we hear comes from “hearsay” and not always from strong scientific evidence.
Food and sleep: how what you eat affects your sleep
What does science say about this? Here we dive deeper into the influence of nutrition on sleep based on recent insights and research. What we can already tell you is that, just as for sleep, regularity is a golden rule for nutrition.
Eat and sleep according to a certain rhythm
We have talked a number of times about our biological clock. A lot in our body works according to that biorhythm. In fact, all the cells in our body work according to a certain rhythm.
The gut is sometimes called your second brain. A particularly beautiful microbiome that connects our intestinal flora to our brain via the vagus nerve, among other things. The complex system, according to neurologist Inge Declercq, is sensitive to melatonin, the neurohormone that triggers your sleep system.
Our biorhythms are regularly adjusted by certain “zeitgebers,” or factors that reset your clock “more correctly. Environmental factors such as light and nutrition play an important role here. Our sense of hunger and satiety is controlled, among other things, by our biological clock. We call this “chrononutrition.
The digestion of food is also regulated thanks to cells in the liver, stomach, pancreas and intestinal system that act on these rhythms. Attention to “chrononutrition” is growing rapidly among sleep researchers.
Fact or fiction?
Do proteins have a positive impact on your sleep?
Research shows that people with better sleep quality tend to have more protein in their diet, writes Merijn van de Laar and others. Higher protein intake is associated with better sleep quality, especially in overweight people. For example, a high-protein diet for four weeks led to improved sleep quality, according to research by Zhou et al., in 2016. Yet there are conflicting results: another study found that more protein was actually associated with shorter sleep duration (Santana et al., 2012). It seems that a balance in this is important.
Inge Declercq writes about tryptophan foods in her book “The Power of Sleep. She does point out that they are certainly not miracle drugs that can solve insomnia, for example. They are good for your body and also have a low glycemic index. So consider: fatty fish, poultry, avocado, legumes, eggs, seeds, nuts and dairy products such as cheese, milk, cottage cheese and yogurt.
Tryptophan is a substance that you cannot make yourself, but must absorb through your diet. Per day you need about 280 mg of tryptophan. It is a building block for serotonin, from which your body later makes melatonin, and also for vitamin B3. Inge Declercq also says in her book that studies show that taking tryptophan in the evening is conducive to falling asleep. Subjective sleep quality improves and waking during the night decreases.
Fats and carbohydrates: less is more?
People who eat more fats often experience poorer sleep quality, according to research by Sutanto et al, from 2020. A diet rich in carbohydrates has also been found to have an adverse effect on deep sleep, a crucial component of recovery during the night (Phillips, 1975). However, research in this area is limited and sometimes methodologically weak. For now, less fat and a moderate amount of carbohydrates seem beneficial for better sleep.
Lamb, pork and beef in themselves contain a lot of protein but, at the same time, a lot of saturated fats. These fats need to be digested and therefore you wake up more often when you eat meat late in the evening.
Eating times and sleep
Does it matter to your sleep what time you eat?
Studies show that eating late, especially shortly before bedtime, can lead to poorer sleep quality. This may be because late meals activate the body when it should be preparing for rest precisely. Eating is at odds with sleeping because we are not made to digest our food at night.
Your body temperature also plays a role. To fall asleep, your core temperature needs to drop slightly. A heavy meal late in the evening puts your metabolism to work and keeps that temperature higher, making it harder to fall asleep. And if you do fall asleep, you’ll wake up sooner because of a full stomach.
Therefore, avoid the following in the final hours before bedtime:
- a large meal in the last three hours;
- caffeine, such as in coffee, black and green tea, cola, and energy drinks;
- alcohol: it might help you fall asleep faster, but your sleep will be more restless;
- nicotine;
- spicy food.
People who eat fatty and/or sugary meals, such as fast food, late at night tend to sleep worse. As your bedtime approaches, it’s best not to eat more, especially fatty and sugary foods. Your blood sugar and cortisol levels will go up, whereas they are best as low as possible to sleep well. Better choose tryptophan-rich foods and limit the quantity.
What if you’re still hungry?
Still hungry right before bed? Then pay attention to the glycemic index (GI) of foods. This indicates the amount of sugars (glucose) in your blood when you eat certain foods. The lower the GI value, the less insulin is needed to process sugar.
Note: this does not mean that you have to omit sugars (or carbohydrates) from your diet in the evening, for example. Until four hours before you go to bed, feel free to eat these, but it is best to choose low-GI foods such as legumes, fruits, vegetables, oatmeal, unsalted nuts or low-fat yogurt.
In any case, avoid soda, candy, ripe bananas, grapes, honey, cereal, white rice or potatoes. The GI of the latter is ideal for daytime because you need a lot of energy then.
Fancy a sleep cocktail to fall asleep quickly? Be sure to read the book “The Power of Sleep” for yourself sometime, but we are already giving you this tip for a sleep cocktail by Inge Declercq: What you need. Half a cup of Greek yogurt, sugar-free almond milk and sour cherry juice or frozen sour cherries. Blend the ingredients into a cocktail and add a little cinnamon or maple syrup for an extra sweet taste. Santé and sleep well!
What does research say about nutrition and sleep?
Milk, kiwis and more: myth or truth?
The effects on sleep of foods such as milk, kiwi fruit and sour cherry juice, have been much debated. Research shows that milk (tryptophan-rich) can have a small positive effect on sleep quality, but the effects are modest (Komada et al., 2020).
Kiwifruit also appears to improve sleep quality, but available research is limited and sponsored by stakeholders (Lin et al., 2011).
Sour cherry juice may slightly increase sleep duration, but again this is based on small-scale studies. And you should already be drinking nearly half a liter, at least two hours before sleeping.
Supplements such as tryptophan and vitamin D may have modest positive effects on sleep (Sutanto et al., 2022; Chan & Lo, 2022). Nevertheless, caution is advised: effectiveness is often limited and some supplements may have side effects. Melatonin, for example, is often misused and may actually exacerbate sleep problems in some cases (Sateia, 2017).
Recent research in the journal Frontiers in Psychology examined the impact of diet on dreams. New research shows that dairy consumption, especially the compound tyramine, especially in people with lactose intolerance, is associated with poorer sleep quality and more frequent nightmares. Possible cause: gastrointestinal discomfort can cause micro-arousals. These are fragments of wakefulness that enhance dream intensity as well as memory. At the same time, from previous research (2005), there is also evidence that some cheeses may actually be associated with pleasant dreams, indicating that the science on this is still divided. A study sponsored by the British Cheese Association showed no connection. Do you live in Belgium or the Netherlands and want to listen to an animated discussion? Then check out this Nerdland podcast from August 2025.
Gluten and sleep
People with coeliac disease or gluten sensitivity also often suffer from sleep problems and fatigue. Pulmonologist and somnologist Reinier de Groot (Dutch Sleep Institute) points out that the cause is still unclear and that more research is needed (Glutenvrij, Dutch Coeliac Association, October 2022). Do you recognise this? Discuss it with your GP.
If you sleep poorly, you eat differently
The connection also works the other way around: if you get too little sleep, what and how much you eat changes. Two hormones play a leading role here. Ghrelin increases your feeling of hunger, while leptin signals that you are full. With sleep deprivation, that balance is disrupted: you get hungrier and feel satisfied less quickly.
American researcher Eve Van Cauter showed that people who sleep shorter hours have less control over their appetite. They also reach for fast sugars and carbohydrates like sweets, bread, and pasta more often. In his book ‘Why We Sleep’, neurologist Matthew Walker describes how sleep deprivation slows down the parts of the prefrontal cortex we use to make sensible choices, while the more primitive urge to eat actually becomes stronger. As a result, test subjects with sleep deprivation clearly ate more calories. The good news: as soon as they slept normally again, this recovered fairly quickly.
Furthermore, those who are tired move less. This quickly creates a vicious circle. And being overweight, in turn, increases the risk of snoring and sleep apnoea. You can read more about that in the difference between snoring and sleep apnoea.
Nutrition and stress?
Over the past 15 years, there has been an increased interest in the scientific research field in so-called “nutritional psychiatry. With this, the interaction between what we eat, our brain and our intestinal system is being studied more closely. More and more scientists are convinced that nutrition is more than the sum of nutrients. So says Michaël Sels, dietician and innovation manager of clinical nutrition at the University Hospital Antwerp (UZA) in De Morgen.
Healthy diets with great attention to vegetables and lots of fruit, or also a large amount of complex sugars and dietary fiber are most promising for the prevention or treatment of disorders related to stress. With a few slices of whole grain bread, pieces of fruit and several hundred grams of vegetables per day, you are quickly at the recommended amount. Other clinical studies revealed similar results: Mediterranean diets have anti-inflammatory effects and lower your stress levels. Keep in mind that it takes some time before you’ll notice any effects. There are no quick fixes here.
Now let stress often be a sleep disruptor for many people. We talked earlier about tryptophan, an essential amino acid. This does appear to impact and calm our human body. This amino acid is the precursor substance of serotonin and of melatonin, remember? Don’t combine it with a lot of saturated fats or sugars, though, because then all those bananas, pumpkin seeds, yogurts or glasses of milk won’t make any sense at all.
Conclusion – Nutrition and sleep
Although research on the relationship between nutrition and sleep is still in its infancy, there are already some important insights:
1. Proteins seem beneficial: including more protein in your diet can help improve sleep quality. Tryptophan is also frequently mentioned as an impactful substance.
2. Avoid consuming too many fats (such as cheese) and refined carbohydrates shortly before bed: these are associated with poorer sleep.
3. Watch the timing of your meals: try not to eat too late in the evening and avoid heavy, high-fat meals right before bedtime.
4. Be critical of supplements: while some supplements like tryptophan may be beneficial, more research is needed to confirm their effectiveness. Often, these substances are already sufficiently present in a balanced diet.
5. Small benefits from specific foods: milk and perhaps kiwis might help, but don’t expect any miracles.
Nutrition and sleep remain complex topics. For now, a balanced diet with attention to timing seems to be the key to better sleep. And as always, consult a doctor or dietitian if you want to drastically alter your diet or try supplements.
Nutrition and sleep: frequently asked questions
Which foods promote sleep?
Foods high in tryptophan, such as oily fish, poultry, eggs, nuts, seeds, legumes, and dairy, can have a small positive effect. A (not too ripe) banana, kiwi, or tart cherries are also often mentioned. Don’t expect miracles: a balanced eating pattern with fixed meal times does more than any single food item.
Which nutrition hinders sleep?
Caffeine, alcohol, nicotine, spicy food, and heavy, fat- or sugar-rich meals late in the evening. Ideally, do not eat a large meal in the last three hours before going to bed.
What is best to drink before bedtime?
Water or a caffeine-free herbal tea, such as chamomile or mint. A glass of (warm) milk is also an option. Avoid coffee, black and green tea, cola, and energy drinks, and don’t drink too much right before bed, otherwise you’ll have to go to the toilet during the night.
Good to know: this article provides general information and is not a substitute for medical advice. Have you been sleeping poorly for a while or are you concerned about your health? Talk to your doctor. Read our disclaimer
Resources
The insights in this article are based on recent scientific research, as described by Merijn van de Laar, PhD, and other published studies. ‘The Power of Sleep’ by Inge Declercq is a book that MindTheBed highly recommends. And the Nerdland podcast for our Flemish and Dutch readers as well, of course!