Spending too much time in front of television and computer screens takes a toll on children's mental health, suggests study.
According to a British government briefing document from Public Health England, inactive lifestyles are also to blame for the negative impact on children's wellbeing, News.com.au reported.
It said higher levels of TV viewing were having a negative effect on children's wellbeing, including lower self-worth, lower self-esteem and lower levels of self-reported happiness.
Children who spent more time on computers, watching TV and playing video games also tended to experience higher levels of emotional distress, anxiety and depression, it said.
Last week, a study found half of all seven-year-olds do not get enough exercise - and girls are far less active than boys.
Only 51 percent of all seven-year-olds in the UK achieve the recommended hour of exercise every day, with the figure being just 38 percent in girls compared with 63 percent in boys.
Half of this age group is also sedentary for an average of 6.4 hours or more every day, experts found.
The study found that children of Indian origin and those living in Northern Ireland were among the least physically active of all seven-year-olds.
The research is published in the online journal BMJ Open.