A study found children spent more than a third of their after-school time using screens, with programmes and gaming accounting for most of the use. Photo: Getty Images
Researchers say more consistent screen time guidelines for children and adolescents is urgently needed.
A University of Otago study published in the New Zealand Medical Journal examines the extent of children's - particularly adolescents - screen time using wearable camera data from an earlier Kids'Cam project.
It involved more than 100 young people aged 11-13 years wearing cameras that captured images every seven seconds.
The researchers found children in the study spent more than a third of their after-school time using screens, with higher rates after 8pm.
Watching programmes and gaming accounted for most of the screen use with television making up 42 percent of the screen time followed by computers at 32 percent.
Senior researcher Dr Moira Smith, from the university's department of public health in Wellington, said screen use was now a part of children's everyday lives and was likely to have increased since the Kids'Cam data was collected.
"It is associated with obesity, poor mental wellbeing, poor sleep and mental functioning and lack of physical activity. It also affects children's ability to concentrate and regulate their behaviour and emotions.
"Screen use rose rapidly during the Covid-19 pandemic, and children in 2023 are frequently spending time online, particularly on smartphones."
She also raised concerns about the content they were being exposed to as well as experiencing sexism, racism and bullying while online.
"Cyberbullying is particularly high among children in Aotearoa, with one in four parents reporting their child has been subjected to bullying while online."
The current laws were outdated and failed to adequately deal with the online world children were being exposed to, she said.
"While screen use has many benefits, children need to be protected from harm in this largely unregulated space."
The authors said their findings reinforced the need for consistent guidelines to promote healthy screen time behaviour for children.
They also recommended further research to monitor the impact of screen on children's wellbeing and work to protect children from harm online.