How much TV children watch accurately predicts whether they will go on to become overweight, a study suggests.

It has previously been shown television is linked to weight gain as children are less active and eat while watching.

Researchers at new zealand's University of Otago looked at how much TV children aged five to 15 watched.

The International Journal of Obesity study found the 41% who were overweight or obese by the age of 26 were those who had watched most TV.

A study by the same team published last year suggested children should watch no more than two hours of TV a day to protect their future health.