Scientists from the University of Aberdeen have found that young children who watch a lot of television are much fatter than those who do not.

The study of two- to six-year-olds found those spending just an hour a day longer in front of the television had on average two pounds more body fat.

But scientists carrying out the research believe the cause is food intake rather than inactivity.

They believe that the children could be snacking unhealthily while viewing, or could be influenced to eat unhealthy food as a result of what they watch.

The findings follow a three-year study by researchers at the university of 89 youngsters between two and six years old.

Children involved in the study watched an average of two hours of TV a day - but those who watched more weighed more than those who watched less.

Dr Diane Jackson, from the university's Rowett Institute of Nutrition and Health, said: "We investigated whether TV viewing is associated with body fatness, physical activity and calories burned.

"Using a range of techniques, including a state of the art method which measures calories burned during daily life, we measured the children's physical activity levels, their body fat and how many calories they used.

"The results showed a clear positive link between how much time per day the children spent watching TV and how fat they were.

"Given that TV programming for young children has increased in recent years, the relationship between TV viewing and diet may be a promising target for future obesity interventions."

The findings are published in the American Journal of Clinical Nutrition.