Smartphones can cut your kid’s sleep, layer on the pounds

By Priyam Vora

Sleepy kids may have a hard time hitting the basketball court or focusing on their homework. And the source of their problems may radiate from the digital world of their smartphones!

Researchers from Brigham and Women’s Hospital in Boston recently reported that the “blue light” glow from using smartphones and other electronic devices too close to bedtime can make it difficult to fall asleep.  But the same study shows that this lack of sleep in kids can result in increasing risks of obesity during  adolescence.

Watching a favorite show on the iPad, checking email, playing games, or responding to a text message in bed at the end of the day before sleeping may seem harmless. However, these habits can start in early childhood and sleep disruption patterns can have long-term harmful effects on a child’s health, sleep experts agreed.

With these habits, the foundations for obesity might already have been laid for your young one.

“It should not be surprising that a sleepy kid may feel more motivated to lay on the couch than he would be to go outside and play,” said Dr. Chris Winter, Medical Director of Charlottesville Neurology and Sleep Medicine, who was not associated with the study.


During the two-week study, 12 adults participants with an average age of 25, were asked to read on an iPad for four hours before bed for five consecutive days, a process that was repeated with printed books. For some, the order was reversed: they started with printed books and moved on to iPads.

Researchers found that the iPad readers took longer to fall asleep and felt less sleepy at night compared to paper book readers. The iPad readers were also more tired than book readers the following day, even if both got a full eight hours of sleep.

The study researchers also surveyed 2,048 fourth- and seventh-grade students, who answered questions about their sleep and smartphone and TV habits. The survey found that children with electronic devices in their bedrooms slept an average of 20.6 minutes less at night than those who slept away from the devices. Additionally, children who slept watching TV, typically slept 18 minutes less than those who didn’t. In general, the survey concluded that children who spent a lot of time watching TV or playing videogames on their devices close to bedtime, reported they slept less.

The research demonstrated that the “blue light” emitted from electronic devices such as the iPad, Kindle or any smartphone has an effect on sleep cycles. The findings of the study are published in the Proceedings of the National Academy of Sciences.

“The blue spectrum light that projects from such screens sends a message to the brain to stop secreting melatonin,” explained Dr. Lisa Medalie, a behavioral sleep medicine specialist at the University of Chicago. “If we expose ourselves to such light leading up to bedtime, clearly that would interfere with our sleep,” said Medalle, who wasn’t associated with the study.

Melatonin is the sleep pattern hormone secreted by the pineal gland, a small gland located near the center of the brain.  A reduction in melatonin at night is directly linked to subjective levels of sleepiness, according to the experts.

“Exposure to this blue light at night can delay your sleep phase and result in greater difficulty to falling asleep,” said Dr. Rakesh Bhattacharjee, an assistant professor of pediatrics at the University of Chicago.


“Exposure to the blue light results in sleep restrictions or sleep debt,” said Robin James, a polysomnography technologist at Ohio Sleep Society. “This sleep loss, in turn, contributes to weight gain and obesity.”

Studies have shown that when a person is sleep deprived, there is less production of leptin and more production of ghrelin resulting in weight gain. Leptin, known as the “satiety hormone,” plays a crucial role in appetite and weight control by signaling the body to stop eating. The effect of ghrelin is opposite to that of leptin. Known as the “hunger hormone,” ghrelin is the hormone which signals the body to eat.

“Excessive sleepiness and disturbed sleep directly affects children’s baseline metabolic rate, making them burn less calories,” said Winter.

The relationship between lack of sleep and weight gain is a strong one, borne out in a variety of studies over the years. Studies have repeatedly shown that both adults and children are more likely to be overweight and obese the less they sleep at night. When children are sleep deprived, they crave foods that are highest in calories, like desserts, chocolate, potato chips and soft drinks.

“Not only does a sleep deprived body want to eat,” James said, “but it craves higher caloric foods since the body burns more calories than a sleeping one.”


The negative effects of sleep deprivation are serious for adults as well as children. Apart from obesity, consistently sleeping less than seven hours in a 24-hour period has been associated with increased risks of cardiovascular diseases, diabetes, depression, automobile and workplace accidents, learning and memory problems and an overall increase in mortality.

With obese kids already a leading health concern among parents, one of the solutions may be as simple as not allowing children to use their electronic gadgets close to bedtime.

Experts suggest a relaxing pre-sleep ritual as a close alternative for kids to fall asleep. While “winding down” activities such as a hot bath, soft music or reading a paperback book would make an excellent sleep ritual, specialists also recommend regular exercise during the day for a good night sleep.

In order to form good sleep habits, doctors also suggest a complete ban on any kind of screen activities whether it is reading, playing or simply viewing.

“This is a matter of sleep hygiene and not medication,” said Bhattacharjee.

Winter agrees. “Turn off that phone and go to sleep!”

Sleep unplugged

(Flickr/Susana Fernandez)
(Susana Fernandez/Creative Commons)

Advice from sleep experts

  • Unwind: Have a 15 to 30 minutes transition period of technology-free time before your kid goes to sleep.
  • Shut down: Make your child’s bed an electronic-free zone.
  • Disconnect your kids: Take the TV out of your child’s bedroom. Offer children a relaxing book to read before bed instead of the remote.
  • Temperature and lighting: Shutting down the lights and setting a comfortable temperature signals the body the right messages.

What lack of sleep does to you

(Flickr/Bryan Ledgard)
(Bryan Ledgard/Creative Commons)

The negative effects may not be visible immediately but lack of sleep in childhood can lead to serious consequences in adolescence

  • Sleepiness causes accidents
  • Sleep loss dumbs you down
  • Sleep deprivation causes serious heart problems
  • Lack of sleep leads to depression
  • Sleep debt ages your skin
  • Sleepiness makes you forgetful
  • Lose sleep. Gain weight.
  • Lack of sleep may increase the risk of death
    (Quoted from Web MD)
Photo at top: Studies show that children reading from an electronic device before bedtime suffer from lack of sleep which in turn leads to obesity in their later years. (Christopher Walljasper/Medill)