Second screens, such as mobile phone and tablets, used as an extension of the TV are having an adverse affect on children's health, according to an expert.
The technology impacts children's health, development and academic performance, claims Vicki Dawson, founder of The Children's Sleep Charity.
She told Cable.co.uk: "We are receiving an increasing number of enquiries from parents of teens regarding sleep issues and many of these are impacted on by the use of technology.
"There is research that shows that screen activities in the hour leading up to bedtime can interfere with melatonin production. We need melatonin to feel sleepy at night and many teens find that it is difficult to fall asleep."
This warning follows the publication of the Ofcom Digital Day: Children's Diary report, which found that 11-15 year olds squeezed in nine and half hours of media consumption into a seven-hour period, thanks to second screens.
As well as poorer performance at school, the lack of sleep could lead to an increased risk of mental health issues, heightened anxiety, weight issues, and hormone and growth problems.