Sleep is affected by many factors, including a person's mental health, light exposure and physical issues. It is also very well known that diet has a strong connection with the quality of sleep. A new study examined how nutrition affects it and found that eating junk food can disrupt deep sleep patterns.

In the latest study, researchers from Uppsala University in Sweden analyzed how an unhealthy high-fat/high-sugar (HFHS) diet impacts sleep in humans. They found fat and sugar in junk food can reduce sleep quality by disrupting the brain's electrical activity.

"Both poor diet and poor sleep increase the risk of several public health conditions. As what we eat is so important for our health, we thought it would be interesting to investigate whether some of the health effects of different diets could involve changes to our sleep. In this context, so-called intervention studies – designed to allow the mechanistic effect of different diets on sleep to be isolated – have so far been lacking," explained Jonathan Cedernaes, a senior author.

The findings of the study were published in the journal Obesity.

Researchers evaluated the sleep patterns and brain electrical activity in 15 healthy men. The participants had normal weight and sleep habits and were given two types of diets of the same calories – a high-fat high sugar diet and a low-fat/ low-sugar diet in random order for a week.

They then found that sleep duration did not differ across the diets. The participants felt their sleep quality was the same. However, the electroencephalogram (EEG) recordings showed that the HFHS diet disrupted the slow waves associated with the brain's electrical activity during deep sleep, making it less restful.

Researchers believe the disruption happens when sugar and fat activate brain pathways and makes people feel more awake. However, more studies are required to understand the mechanism.

The slow-wave sleep naturally declines with age, but, following a healthy diet can help im[prove its quality, Cedernaes said.

Food to include for a good night's sleep

Eating certain foods before bed can help improve the quality of sleep. Here are some of the food with sleep-promoting properties:

  • Almonds
  • Fatty fish
  • Malted milk
  • Kiwi fruit
  • Chamomile tea
  • Tart cherry juice
  • Bananas
  • Low-fat yogurt
fast food
A recent study found that eating junk food can disrupt deep sleep patterns. ebru CC BY 2.0