Watching YouTube hurts teenagers' health more than Netflix or TV

YouTube may be more harmful to teenagers' sleep than Netflix or traditional television, a new study says. 

Researchers from Flinders University in Australia found that half an hour spent on the app under a blanket results in a 13-minute delay in going to sleep. That's the equivalent of every 15 minutes of browsing reducing the likelihood of falling asleep by 24 percent.

The research team called YouTube dangerous for sleep because of its short videos, auto-play and recommended clip features, which cause users to lose control and become glued to their screens for long periods of time.

The study was conducted in eight schools in Adelaide, South Australia, and was published in the Journal of Sleep Medicine.

However, in a sample of 700 teens ages 12 to 18, those who watched TV for the same amount of time before bed went to bed an average of nine minutes earlier - the researchers suggest that the results for Netflix would be similar. 

Teens reported how much time they spent on devices and apps in the hour before bedtime, during bedtime, and how long they slept on school nights.

Each of the children estimated the amount of time they spent on devices and apps.

The results showed that each went to bed around 10 p.m., turned off the lights by 10:36 p.m., and then needed about 30 more minutes to fall asleep.

Almost every teen (98%) used at least one device an hour before bedtime - a phone, laptop or TV - and three-quarters reported using it during bedtime.

Phones were the most popular (98%), followed by nine in ten who said they used a laptop and almost seven in ten who said they watched TV.

The analysis showed that while YouTube was the third most popular app that half of teens accessed, users spent the most time on it at bedtime - more than 25 minutes.