Girls who have TVs in their bedrooms are a third more likely to be fat, a study reveals.
Experts said watching the telly in bed is an obesity risk factor and parents should consider banning them.
Little girls who have TVs in their bedrooms are a third more likely to grow up fat, experts have warned University College London experts looked at more than 12,500 British youngsters.
They found 7-year-olds who had televisions in their bedroom were significantly more likely to be overweight by age 11.
For girls the risk was 30 percent higher, while for boys it was 20 percent.
More than half of kids had their own televisions.
They also raised fears that other digital devices such as smartphones, tablets and laptops could have similar effects.
Lead researcher Anja Heilmann, from the UCL Institute of Epidemiology & Health Care, said: “Childhood obesity in the UK is a major public health problem. Our study shows that there is a clear link between having a TV in the bedroom as a young child and being overweight a few years later.”
“Childhood obesity prevention strategies should consider TVs in children’s bedrooms as a risk factor for obesity.”
One in three kids leaves primary school too fat, with obese children five times more likely to grow into obese adults.
Being too heavy increases the chances of type 2 diabetes, heart, liver disease and several common cancers.
The study was published in the International Journal of Obesity.
It also found the greater the screen time, the more likely girls were to be tubby, although the same was not true for boys.
Experts said it was likely due to the fact that lads are more physically active at that age.
Heilmann added: “The causes of overweight and obesity are complex and multiple.”
“Screen time is part of the bigger picture and further research is needed among older children and adolescents, as the use of screen-based media including computers, mobile phones and tablets increases with age.”
Russell Viner, a professor at the Royal College of Pediatrics and Child Health, said the findings must be taken “very seriously.”
He said: “Urgently tackling the childhood obesity epidemic is absolutely vital.”
“We know that high levels of screen time expose children to increased risks of being overweight on a number of fronts, creating a damaging combination of a more sedentary lifestyle, increased exposure to junk food advertising, disruption to sleep and poorer ability to regulate eating habits when watching TV.
“The study adds yet more weight to our recommendations for a strict ban on junk food advertising before the 9 pm watershed.”
A spokesman from the Obesity Health Alliance also called for tougher rules around junk food advertising.
She said: “Children’s lifestyles inevitably have an impact on their weight and with childhood obesity rates at an all-time high level, we need to get to grips with the issue to protect the future generations.
“It’s a fact of life that children’s screen time has increased.”
“What’s worrying is the increased opportunities this gives the food industry to target them with adverts for unhealthy food and drink.”