An unhealthy diet can be directly connected to poor quality of deep sleep, as per a small-scale study by researchers at Sweden-based Uppsala University.
What is deep sleep?
The third stage of sleep, deep sleep is when all the repair, restorative and other important functions such as muscle growth happens.
The researchers, via their study which was published in the journal Obesity, analysed how consumption of junk food can impact one's sleep cycle.
The process of the survey
During the survey, 15 healthy regular-weight young male participants were asked to maintain a healthy as well as unhealthy diet in random order. The study was done in two sessions.
Once the participants' sleep habits were ascertained, that it falls between the normal range of seven to nine hours per night, they were given diets randomly. The unhealthy diet had more sugar and saturated fat plus contained more processed food products. Each person's diet lasted a week and sleep, activity and meal schedules were monitored.
The researchers speak
"What we saw was that the participants slept for the same amount of time when they consumed the two diets. This was the case both while they were following the diets, as well as after they had switched to another, identical diet," said Jonathan Cedernaes, Associate Professor at Uppsala University.
The researchers were looking at slow-wave activity, which is a measure which reflects how restorative in nature one's deep sleep is.
"Intriguingly, we saw that deep sleep exhibited less slow-wave activity when the participants had eaten junk food, compared with consumption of healthier food," Cedernaes said.
The effect of this seeped into the second night as well once the participants of the survey went on an identical diet.
In conclusion, shallower deep sleep was the result of an unhealthy diet. Hence, from the perspective of sleep, more importance should be given to diet, they added.
