Teenagers are skipping meals, sleep and doing their homework to spend more time online, according to a new report which asked young people themselves how their time on the internet affected their lives.
Netsafe's research also found teenagers reported fighting more with friends and whanau because of time surfing the internet.
Netsafe chief executive Martin Cocker said they surveyed 14 to 17 year olds, of which 47 per cent said very often or sometimes had conflict with their family or friends over their time online.
"That's the thing that you find when you talk to parents, they say "I gave them their device and they won't get off it and it leads to fights and they won't come to dinner", and that sort of thing, so it's good to do this research and find out that that is incredibly common.
"If young people are admitting that it's a problem it's a lot easier to deal with them.
"For everybody, but definitely for young people, you've got to get them to eat and you've got to get them to sleep because if you're not eating and sleeping that's going to affect other aspects of your life, certainly your education."
Mr Cocker advised parents to set limits either by forcing rules or having conversations about time online, addressing issues and checking up on them.
"If you are one of the 10 per cent of young people who are often having problems then you are looking for your parents to help you out," he said.
"I think it's important to have this conversation about time that young people spend, just sit down and talk to them about it. How much time do you spend on different things? You know, what do you think the impact is?
"If you're lucky your child will say to you 'look I spend too much time doing these things and it's having a negative impact' and that'll make it easy. If not, you're going to have to lay that out and then just set rules - you can have really formal setting of rules, you can have a document, Netsafe has one of those to download, or you can do it informally - you can discuss it and then keep coming back to that conversation but you just need to address it."
However, Mr Cocker added not all time spent online is the same. Sometimes children and teenagers will be playing games, but other times they will be doing homework.
"We're not saying time online is harmful because it's time online, we're saying it's harmful because it's impacting elsewhere."