How junk food could harm your sleep: a simple explanation

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Scientists from Uppsala University, in Sweden, studied how eating junk food impacts sleep.

They discovered that after eating unhealthily, the quality of people’s deep sleep got worse compared to when they ate healthily. This study has been published in a scientific journal named Obesity.

The Importance of Sleep and Diet

Sleep and diet are two very important parts of our lives. They help us stay healthy and feeling good. If we don’t eat well or sleep well, we can end up feeling unwell or getting sick.

Professor Jonathan Cedernaes, a doctor and teacher at Uppsala University, tells us that both poor sleep and a bad diet can increase our chances of getting certain diseases.

What we eat can change how we sleep. For example, eating lots of sugar can lead to poorer sleep.

But sleep isn’t just about being awake or asleep. It has different stages, like deep sleep, which is really important for things like controlling hormones in our body.

And different parts of our brain are involved in different stages of sleep, which can affect how refreshing our sleep is.

However, sometimes, things like not being able to sleep (insomnia) and getting older can make the quality of our sleep worse. The scientists wanted to know if eating different diets could do the same thing.

The Study

The study was quite difficult to do because it needed people to stay in a sleep laboratory for several days. So, they could only have 15 people in the study.

All these people were young, healthy men who had normal sleep habits, sleeping for an average of seven to nine hours every night.

The scientists gave these men two different diets to eat in random order. One diet was healthy, and the other was unhealthy, with more sugar and saturated fat and lots of processed food.

But both diets had the same amount of calories, based on what each person needed every day.

The men ate each diet for a week. During that time, the scientists watched their sleep, activities, and when they ate their meals.

After each diet, the men spent time in the sleep laboratory. They first had a normal night’s sleep, where the scientists measured their brain activity to monitor their sleep.

Then, they had to stay awake in the sleep laboratory before being allowed to sleep again, and their sleep was recorded again.

The Results

What the scientists found was quite interesting. Even though the men ate two different diets, they slept for the same amount of time on both diets. They also spent the same amount of time in different sleep stages on both diets.

But when the scientists looked at the quality of their deep sleep, they noticed something. After eating junk food, the men’s deep sleep was not as good as after eating healthy food.

This was measured using something called “slow-wave activity,” which can tell us how good our deep sleep is.

Even when the men switched back to a healthy diet, their deep sleep was still not as good. This is similar to what happens when people get older or have trouble sleeping.

So, scientists think that maybe we should pay more attention to what we eat to help improve our sleep.

What Does This Mean and What’s Next?

We don’t know yet how long the effects of an unhealthy diet on sleep last. The scientists also didn’t look at whether the poorer deep sleep changed any of the functions that deep sleep is supposed to help with.

In the future, it would be interesting to see if poorer sleep can affect things like memory, which is a lot controlled by sleep. It would also be good to know how long these effects last.

And it would be interesting to find out what exactly in an unhealthy diet makes our deep sleep worse. Is it the sugar, the fat, or something else?

The study only lasted for a short time, and maybe a longer study with an even unhealthier diet would show even bigger effects on sleep.

In the end, this study helps us understand more about how important both diet and sleep are for our health. So, let’s try to eat healthy food and get a good night’s sleep!

The study was published in Obesity.

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