Allowing your child to have a TV in their bedroom could be ruining their waistline, scientists claim.
A new study found that youngsters weighed more if they were able to stay up all night flicking the remote.
They are also more likely to fall behind at school as they spend less time reading books, researchers warn.
The Iowa State University study comes after a landmark paper in June that found more than half had TVs in their bedroom at age seven.
A new study found that youngsters weighed more if they were able to stay up all night and watch various TV channels in their bedroom
Professor Douglas Gentile led the review published in the journal Developmental Psychology, which was based on three existing studies.
He has now called for parents to make sure their children never have access to TVs in their room, if they don’t want their children to end up obese.
Professor Gentile said: ‘It’s a lot easier for parents to never allow a TV in the bedroom than it is to take it out.
‘When most children turn on the TV alone in their bedroom, they’re probably not watching educational shows or playing educational games.
‘Putting a TV in the bedroom gives children 24-hour access and privatizes it in a sense, so as a parent you monitor less and control their use of it less.’
What else did the researchers find?
After assessing the three studies, the researchers found when there was a TV or video game console in the bedroom, spent spent less time reading.
They also slept less and didn’t participate in other activities as often, according to the scientists.
NO TELEVISIONS IN THE BEDROOM
A recent study found that children who have a consistent bedtime routine and limited screen time are at lower risk of being obese.
A team from Ohio State University in Columbus analysed data on 10,955 youngsters born in the UK from 2000 to 2002.
They looked at parents’ descriptions of household routines and children’s behaviour at three as well as measurements of children’s height and weight at age 11.
They discovered that three-year-old children who had regular bedtimes, mealtimes, and limits on their television/video time were better at controlling their feelings and impulses, the authors found.
More chaotic routines meant they at age three meant they had poorer emotion regulation and were more likely to be obese at 11.
As a result, these children did not do as well in school and were at greater risk for obesity and video game addiction, Professor Gentile said.
The effects were tracked over a period of two years on nearly 5,000 children.
The study also found children with bedroom media watched programs and played video games that were more violent, which increased levels of physical aggression.
University College London researchers suggested last month that keeping a TV in the living room allows parents to supervise how much their children are watching.
Dr Anja Heilmann, lead researcher of that study of 12,500 children, suspected that lack of sleep may play a role.
Excessive TV watching and use of other screen-devices and insufficient sleep have long been linked to obesity in adults.
Other possible theories for the link include children snacking more while they watch TV, seeing more junk food adverts and simply sitting around more.