Watching television disrupts children's' normal response to food
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
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.