Watching TV for 3 hours daily may up diabetes risk

Parents, take note! Being glued to television or video games for more than three hours a day may put your children at increased risk of developing diabetes, a study warns.

Researchers found that both adiposity, which describes total body fat, and insulin resistance, which occurs when cells fail to respond to insulin, were affected by longer hours of watching television and using computers.

"Our findings suggest that reducing screen time may be beneficial in reducing type 2 diabetes risk factors, in both boys and girls, from an early age," said Claire Nightingale, research fellow at St George's, University of London in the UK.

Researchers based their findings on a sample of nearly 4,500 nine to 10-year-old pupils from 200 primary schools in London, Birmingham and Leicester.The children were assessed for a series of metabolic and cardiovascular risk factors, including blood fats, insulin resistance, fasting blood glucose levels, blood pressure and body fat.

They were asked about their daily screen time to include TV, computers, and games consoles.

Complete information was obtained for 4,495 (2,337 girls and 2,158 boys) out of the 5,887 who took part in the study between 2004 and 2007; additional data on physical activity was also available for 2,031 of them.

Around a third of the children spent less than an hour of screen time a day, but 28 per cent of the children



said they clocked up one to two hours; 13 per cent said their tally was two to three hours; and 18 per cent said they spent more than three hours looking at screens every day.

Trends emerged between screen time and ponderal index—an indicator of weight in relation to height, and skinfolds thickness and fat mass index—indicators of total body fat.Researchers found that these levels were all higher in children reporting more than three hours of daily screen time than in those who said they spent an hour or less on it.

The team also noted that there was a strong trend between levels of screen time and higher levels of leptin, the hormone that controls appetite, and insulin resistance. The trends remained significant even after taking account of potentially influential factors, including physical activity levels, researchers said.

Previous studies in adults had indicated that spending a lot of time in front of a screen is linked to a heightened risk of weight gain and type 2 diabetes, but until now it has not been clear that children might also be at risk.

"It would be very difficult to carry out this research today as smartphones and tablets are so universal. Children today therefore spend even more time looking at a screen than when the original dataset was taken," Nightingale said. 

The study was published in the journal Archives of Disease in Childhood.