Almost all of us have experienced an uncomfortable night of tossing and turning after a heavy or greasy dinner. Under this pretext, science has gone one step further to demonstrate that the relationship between what we eat and how we rest is completely bidirectional, making what we eat determine whether we are going to rest better or worse. And the most surprising thing is that sleeping poorly can cause us to need to consume more sugar the next morning.
A Granada studio. In February 2026 the magazine European Journal of Nutrition published a revealing investigation led by the University of Granada, where researchers monitored the habits of 146 adults with obesity. To do this, they used special watches to analyze accelerometry over a period of 14 days, to later cross-reference the activity data with dietary surveys of what had been consumed throughout the day.
Prohibited items. One of the most interesting conclusions reached was undoubtedly the relationship between certain foods and poor rest. And to be clear, the elements that should be prohibited at our dinner are the following:
- Saturated fats.
- Eating excess protein and, more specifically, eating red meat for dinner.
- French fries, or fried foods in general, reduce the quality of sleep.
- Alcohol is one of the classics on this topic, since, although it generates a feeling of sleep, it destabilizes its quality.
- Large meals cause slow digestion and cause nighttime awakenings, preventing you from entering into a deep and restful sleep.
Highly recommended foods. On the contrary, the passport to restful sleep seems to lie in another type of nutritional profile. Interestingly, carbohydrates, often demonized at night, were associated with better rest in this study. Although we are not talking about sugar directly from the sugar bowl, but rather complex carbohydrates, such as brown rice or potatoes, because they help transport tryptophan to the brain.
But in addition, the consumption of oily fish such as salmon or sardines is also recommended, since they are rich in omega-3 and especially tryptophan.
The reasons. As we see, tryptophan is key in the diet to induce quality sleep, and it is no wonder. Biochemistry tells us that the tryptophan that we ingest through the diet is converted into serotonin and, subsequently, that serotonin is transformed into melatonin, the well-known sleep hormone. And for this chain to work we need very important factors such as vitamin B6, magnesium or zinc.
But this also adds to a much less difficult digestion when talking about foods that are barely fatty and that do not require a lot of work on the part of our body and that do not invite reflux symptoms to appear that can be really annoying at night.
Specific foods. With scientific support behind it we find the kiwi, since here a trial pointed out that eating two kiwis, one before going to sleep, reduces the time to fall asleep by 35%. But it also increases sleep duration by 13% due to its contribution of antioxidants and natural serotonin.
Additionally, green leafy vegetables such as spinach, chard or lettuce provide magnesium and tryptophan. And if vegetables are not for you, we also have eggs, either boiled or in an omelet, which provides tryptophan and vitamin B6, along with the classic grilled chicken breast, which is also an excellent source of tryptophan.
The rebound effect. However, the true clinical contribution of the research is to show that this problem is, in reality, a cycle that feeds on itself in a dangerous way. Here the researchers found that when participants experienced a poor night’s sleep, breakfast was marked by a higher consumption of sugars and a lower intake of fiber.
Images | Slaapwijsheid.nl Debbie Tea
In | We have accepted that “deep sleep” is the standard for sleep quality: science points in another direction
