Junk food can disrupt sound sleep
People who sleep poorly tend to eat foods that are too fatty and too sweet afterwards. But does diet also affect sleep? In fact, a meal high in fat and sugar in the evening seems to impair the quality of deep sleep
Ready-made pizza versus salmon and vegetables
Researchers at Uppsala University recruited 15 healthy young men for their experiment. They were randomly assigned either a healthy or a rather unhealthy diet plan, which they were asked to stick to for a week. After that, they switched to the other option.
During the unhealthy week, participants were given junk food meals high in saturated fat and sugar, such as pizza, packaged meatballs, or chocolate waffles.
The healthy weekly plan included meals that contained little fat and sugar but more fiber, such as unsweetened muesli and yoghurt and salmon with vegetables.
The calorie content was the same in both weeks of the diet and was adjusted to the needs of each participant. The diet was changed after one week. At the end of each week, the test subjects spent two nights in a sleep laboratory, which enabled a precise analysis of the sleep phases.
No differences in sleep duration
The result: “We found that the participants slept for the same length of time on both diets,” explains Jonathan Cedernaes, professor of medical cell biology at Uppsala University. The researchers also found no differences in the length of the various sleep phases – deep sleep, light sleep and dream sleep (REM sleep).
However, the detailed analysis of deep sleep, which we go through several phases of every night, revealed serious deviations. They are crucial for physical and mental recovery: During this time, the body secretes growth hormones, breaks down the stress hormone cortisol, and newly learned things are consolidated in the memory
Less restful deep sleep
“In particular, we looked at slow brain wave activity, a measure of how restorative deep sleep is,” explains Cedernaes. “Interestingly, we found that slow wave activity during deep sleep was lower when participants had eaten junk food than when they had eaten healthier foods.”
The researchers cannot yet say how long the effects of an unhealthy diet on sleep last. It is also unclear which components of junk food disrupt deep sleep – and the mechanisms by which this happens. “It would also be interesting to check whether the shallower deep sleep impairs certain functions that are regulated in this sleep phase,” says Cedernaes.
Mediterranean diet for poor sleep?
Similar changes in sleep to those observed here also occur in old age and in cases of insomnia. The doctor suspects that diet may play a greater role in sleep problems than previously assumed.
For example, you can follow the Mediterranean diet – on the one hand, it is based on a lot of plant-based food, healthy oils, fish and nuts, and on the other hand, it contains little saturated fat, white flour and sugar. You can’t go wrong with this diet: in particular, its positive effect on cardiovascular health has already been proven in many large studies.
In the UAE
The UAE’s fast-food scene is incredibly diverse, offering a wide range of international options. However, the fast-paced lifestyle often leads residents to rely on unhealthy food choices, contributing to long-term health issues like obesity, diabetes, and heart disease.