Electronics in the bedroom doubles risk of obesity in kids

Health policy needed to encourage removing electronic devices from bedroom, contend sleep researchers. Printed books are a good alternative.

Lesley Young - 31 October 2017

Kids who have a computer or TV in their bedroom and who use it heavily one hour before bedtime are twice as likely to be obese compared to kids who do not have these devices in their bedroom, according to UAlberta research.

"We also found that using any electronics in the bedroom before bedtime, including cell phones, had a negative impact on kids' sleep duration and sleep quality," said Nomathemba Dube, lead author of the study and a PhD student with UAlberta's School of Public Health. "Even just having access to electronics, but not using them before bedtime, was associated with poorer sleep and increased obesity risk."

The study, which surveyed 2,334 grade 5 children and their parents in Alberta, showed that sleep duration was shorter by approximately 10 minutes for kids who used cell phones and computers in the bedroom, and by almost eight minutes for those who had or watched TV.

"Even as little as a 15-minute delay in sleep can have huge consequences on our biological systems," explained Dube. "Electronic devices emit blue light which suppresses our main sleep hormone melatonin and disrupts our sleep cycle. When melatonin suppression is prolonged, we get fatigued and stressed. Stress releases the cortisol hormone which starves our brain of glucose. As a result, we crave sugary foods and are therefore more likely to reach for them. Insulin, our number one fat storing hormone, will be activated, causing us to store more fat and to gain weight."

While research has shown that watching TV before bedtime negatively impacts sleep, this the first study to look at a variety of electronic devices, and also whether just having them within reach versus using them makes a difference.

The findings also apply to adults, she added.

Printed books are a safe alternative

The big surprise came when the researchers examined an alternative-reading old-fashioned printed books before bedtime.

"Our findings suggest that sleep duration, sleep quality, and weight status are better among children who do not have electronic devices in the bedroom and who frequently read a book during the hour before sleep as opposed to those who use devices during this hour," said Dube.

The researchers believe that books have a calming effect.

"Reading an enjoyable book, in dim light, helps transition us to sleep mode. They reduce our stress hormones and promote the production of melatonin," explained Dube. "So the message is really that we should not bring electronics into bed with us, but we should bring a book."

Public policy needed

The researchers contend that based on their research findings, the government needs to develop recommendations that discourage the presence of electronics in the bedroom as well as use before sleep.

"Think about how many electronic devices our young generation are juggling," said Dube. "This is extremely important. If we can improve the lifestyle of this generation when they are young, then we can have a positive impact on sleep and health for future generations."

Currently, the study authors are researching practical solutions for families to apply to improve sleep and physical activity for children.

"For now, I recommend parents come up with novel ways to keep electronics out of the bedroom, such as books or board games, and limit the use of devices to less than two hours a day and well before sleep."

The study was published in the International Journal of Behavioral Nutrition and Physical Activity.