Researchers from the Harvard School of Public Health and Children's Hospital Boston found that each hour increase in television viewing resulted in the consumption of an additional 167 calories.
The report, which confirms the well-documented observation that television increases the risk of obesity, found that the more television children watched, the higher their total energy intake levels. This was primarily as a result of increased consumption of 'junk foods', such as candy, sodas and snacks.
"We've known for a long time that television viewing is a risk factor for overweight, though the common perception is that this is due to the fact that it's a sedentary use of time," said Jean Weicha, lead author of the study, which appeared in this month's issue of the Archives of Pediatric and Adolescent Medicine.
"This study provides evidence that television is effective in getting kids to eat the foods that are advertised, and this drives up their total calorie intake," she added.
The researchers collected data on dietary patterns and television viewing habits for around 550 11-12 year-olds in the Boston area, and then repeated these measurements 19 months later.
As well as an increase in calorie intake, the researchers found that each additional hour of television viewing was also independently associated with increased consumption of foods commonly advertised on television, and these foods were shown to be responsible for much of the calorie increase. Viewing time seemed to have the strongest connection to additional consumption of sodas.
While further research on this topic is necessary, particularly on the amounts of advertising necessary to influence dietary choices, Wiecha said her team's results have important implications for parents and the food advertising industry.
"Basically, we concluded that kids in this study eat what they watch. This should help inform discussions about food marketing aimed at children," she said.
Television advertising has been said to account for around 75 percent of food manufacturers' advertising expenditures. In 1997, when the last data for the current study was collected, the food industry spent around $11bn on advertising.
And around a quarter of food manufacturers' advertising budget was spent promoting candy, cookies, snacks and sodas, while only 5 percent of the budget was spent on advertising fruits, vegetables, grains, beans, meat, poultry and fish.
The American Academy of Pediatrics has long recommended limiting children to no more than two hours of television per day to decrease sedentary time and exposure to content that may encourage a range of negative behavior.
"In the absence of regulations restricting food advertising aimed at children, reduction in television viewing is a promising approach to reducing excess energy intake," concluded the current study.