CHILDREN who spend too much time watching TV and playing computer games are in danger of becoming obese and could develop mental health problems.

Researchers at Bristol University have helped produce a report, published today, that shows that while children born at the start of the 21st century are already adept at juggling technology, they are storing up problems for themselves later in life.

Researchers from the university have for the first time asked ten and 11-year-olds about their experiences of operating several screens at once.

They have found that it is common for the youngsters to watch television while also using interactive devices such as laptops, smartphones and handheld games.

The academics warn parents need to consider not merely banning televisions from bedrooms but to look at overall time limits on screen use for the sake of their youngsters' health.

The study entitled I'm on it 24/7 at the moment, is published today in the International Journal of Behavioural Nutrition and Physical Activity. It was conducted by researchers from Bristol with others from Loughborough because of concerns that a sedentary lifestyle, linked to spending lots of time watching TV and playing computer games, could increase the risk of obesity, lower mental well-being, and cause health problems in later life.

It is now possible to view television "on demand" via the internet, play computer games on laptops, on hand-held devices or mobile phones, and keep in contact with friends using text, Facebook, Skype, and MSN – all at the same time.

Before this study, no one had asked children whether they used several screens and what they thought about it. The researchers questioned 63 ten to 11 year olds and found that the children enjoyed looking at more than one screen at a time. They use a second device to fill in breaks during their entertainment, often talking or texting their friends during adverts or while they were waiting for computer games to load. TV was also used to provide background entertainment while they were doing something else – especially if the programme chosen by their family was considered "boring".

Dr Russ Jago, from the University of Bristol's Centre for Exercise, Nutrition and Health Sciences in the School for Policy Studies, said: "There is a shortage of information about the nature of contemporary screen viewing among children especially given the rapid advances in screen-viewing equipment.

"For example, TV programmes are watched on computers, games consoles can be used to surf the internet, smartphones, tablet computers and hand-held games play music, video games provide internet access, and laptops do all of the above."

One of the study's respondents said: "I'm on my DSi and my laptop. On my DSi I'm on MSN and on my laptop I'm on Facebook and then the TV is on."

Dr Jago added: "Health campaigns recommend reducing the amount of time children spend watching TV. However, the children in this study often had access to at least five different devices at any one time, and many of these devices were portable. Children could move the equipment between their bedrooms and family rooms. This suggests that we need to work with families to develop strategies to limit the overall time spent multi-screen viewing wherever it occurs within the home."