A quarter of teens admit their grades have suffered because of how much time they spend mucking around on their devices, a new survey has found.
Netsafe chief executive Martin Cocker says if 26 percent of teens are willing to admit that, the true number is likely to be a lot higher.
"You've given them a device full of games, apps and services that are designed to keep your attention, and they do that," he told The AM Show on Monday.
Netsafe's survey, released on Sunday, also found 47 percent of 13- to 17-year-olds have come into conflict with friends and family over their excessive time online and a third have gone without sleep and food.
But only 10 percent were willing to admit it's caused them real problems.
Cocker says that doesn't mean parents should immediately confiscate their kids' devices, however, as they can also be used to learn. Most intermediate and secondary schools nowadays even require pupils to have devices, such as Chromebooks.
"The devices themselves are not harmful... the devices are full of good stuff. We're not saying they shouldn't be on them - we're just saying you've got to recognise the impact."
That impact can be minimised by encouraging kids to spend their time online and on devices wisely.
"We've got to say to young people, 'You can't use the device after this time - you've got to go to sleep.' Or, 'You need to have a break from that to do something else.'
"The second thing is to think about what they're actually doing on their devices. If you say to them, 'Two hours a week, I expect you to go to your room and do your homework,' clearly they're not going to spend those two hours doing their homework. You might need to say to them, 'Yes you can have the device, but if you are doing this on it - not something else.'"
And he reckons it's a good thing a significant number of teens are willing to admit their time spent online might be detrimental.
"That also opens the door to do something about it. If they were saying, 'No, this is not affecting school, this is not affecting my life,' it would be much harder to say to them, 'You've got to stop.'"