NEW YORK (Reuters Health) - Watching television disrupts children's' normal response to food -- they will eat more while they're sitting in front of the tube, whether or not they're really hungry.
"These data, combined with those from other studies, support recommendations to reduce television watching and restrict eating while watching television as part of a healthy lifestyle," Dr. Jennifer L. Temple and colleagues from the University at Buffalo, New York, conclude.
Temple and her team looked at how television affected "habituation to food cues." Habituation is the phenomenon that occurs when a person repeatedly provided with a food will eventually lose interest and stop eating it once they are full. Providing a new, unfamiliar food can disrupt this process, and a person will start eating again even if they're not hungry. Non-food stimuli may also disrupt habituation if a person's attention is distracted.
In the first experiment, the researchers had 30 normal-weight kids ranging in age from 9 to 12 perform a computer task to earn points to eat food. The task consisted of 10 two-minute time blocks. For the first 7 blocks, kids worked for points to eat half a junior cheeseburger. For the final 3, some children continued to work for pieces of cheeseburger, others worked for French fries, and the third group worked for cheeseburgers while watching television.
While the kids who didn't watch television and were continually offered cheeseburgers as rewards eventually lost interest in the food, the children offered French fries and those who finished the task while watching television started eating again, the researchers found.
The television group and the French fry group spent more time responding to the computer task and consumed more calories than the third group confined to the same food without the distraction of television.
In the second experiment, researchers provided children with 1,000 calories worth of a favorite snack food and told them they could eat as much or as little as they wanted. Some of the children watched a 23-minute television show, others watched a 1.5-minute repeating loop of a television show, and the rest didn't watch television.
The researchers theorized that the repeating television loop would not require the children's constant attention.
The children watching the continuous television show consumed more calories (500) and spent more time eating (21 minutes) than the television-loop and the no-television groups combined, the researchers found.
Given that kids tend to eat high-calorie foods when watching television, snacks in front of the tube have the potential to "profoundly" affect how many calories children consume, even if the time they spend snacking is short, the researchers note.
They call for additional research to determine whether television's effect on habituation is different for normal-weight and overweight kids.
SOURCE: American Journal of Clinical Nutrition, 2007.