Television can make toddlers less clever and fatter if they watch more than two hours a day, according to a new study.
Researchers at the Universities of Montreal and Michigan carried out a study over eight years looking at the amount of television a toddler watches, and comparing this to their academic development.
They discovered that two-year-olds who were allowed to watch two hours of television a day were more likely to be obese later in life and more likely to do worse at school.
They were less likely to take exercise and more likely to eat junk food and drink fizzy drinks.
The children who watched the most television were at risk of obesity and bullying, said the researchers.
The study looked at more than 1,300 children between the ages of two and four, measuring their television viewing habits.
Then when they reached the age of ten, their academic performance and body mass index were measured.
If toddlers watched more than two hours of television a day, their academic performance was on average 7 higher chance of them being bullied.
Dr Linda Pagani, of Montreal University, is reported in the Daily Telegraph as saying: "Early childhood is a critical period for brain development and formation of behaviour.
"High levels of TV consumption during this period can lead to future unhealthy habits. Although we expected the impact of early TV viewing to disappear after seven and a half years of childhood, the fact that negative outcomes remained is quite daunting."
It is a bit scary. In one way it's kind of obvious that too much TV could lead to these problems - but then it's also easy to see how toddlers could spend a couple of hours in front of the telly, even just while parents are getting ready for work, or cooking dinner.
How much TV do your kids watch?