Many of us eat lunch parked in front of a computer, but that habit might be boosting our appetite for dessert, a small study suggests.
In a lab study of 44 men and women, researchers found that those who ate lunch while playing a computer game ended up eating more cookies 30 minutes later than those who'd had their lunch with no distractions.
Researchers say the computer users had a fuzzier memory of their lunch and felt less full afterward compared with the computer-free lunch group.
This suggests, they say, that distractions like computers and TV muddy our memories of mealtime, which in turn may have real effects on appetite.
"We think that memory for recent meals influences the amount of food that we select and then consume at a subsequent meal," researcher Jeffrey M. Brunstrom, of the University of Bristol in the UK, said.
"When our memory is poor," he said, "then at a subsequent meal we tend to select and consume a greater amount of food."
Eat more when watching TV
Past research has suggested that people are prone to eat more when they dine in front of a TV instead of at the kitchen table, possibly because they are paying more attention to the screen than to what their stomachs are telling them.
"We know from several studies that distraction can increase the amount that people consume in a meal," Brunstrom said. "Here, we extend this finding to show that the effects of distraction last beyond a meal."
The study, published online in the American Journal of Clinical Nutrition, involved 44 volunteers who were assigned to one of two groups. In one, participants ate a set lunch while playing solitaire on a computer; those in the other group had the same meal with no distractions.
Thirty minutes after the meal, both groups took a cookie "taste test," in which they could sample as many of the sweet treats as they wanted. They were also asked to recall all nine items they'd eaten at lunch, and the order in which the foods were served.
On average, the researchers found, the computer group ate roughly 1050kJ worth of cookies, while their counterparts ate only half as much.
In addition, the computer group had more difficulty remembering the order in which their lunchtime fare was served, and typically reported feeling less full after lunch.
The findings suggest that effects on memory might account for the greater cookie craving in the computer group, according to Brunstrom's team.
The study was, of course, conducted under controlled lab conditions. Whether the findings hold true in the real world where many factors could affect what and how much we eat is unknown.
Future studies may be needed
Brunstrom said he and his colleagues plan to study that question in the future.
For now, he said, "one implication is that we should avoid eating while distracted, which means eating away from our computer screens and TV sets."
And what about non-technological distractions, like having a conversation during dinner or reading the newspaper at breakfast?
There's some evidence they could thwart your diet, too. One lab study found that both eating while watching TV and eating with friends boosted kilo joule intake to a similar degree, versus eating distraction-free. Another found that people ate more when they listened to a recorded story during their meal.
Brunstrom and his colleagues say their findings are particularly relevant in today's technology-driven, "multi-tasking" world, where people are increasingly dining in front of a screen. And that includes children, they note; one US study found that up to a quarter of kids' kilo joule intake occurs in front of a TV.
(Reuters Health, Amy Norton, December 2010)