Distracted eating may be a prescription for mindless overconsumption — even hours later

By Janet Raloff

Web edition: January 31, 2011

There’s little doubt that humanity has been tipping the scales at increasingly higher weights and rates. A study now lends support to the idea that meal-time distractions can mask the cues that we really have eaten quite enough. Moreover, it finds, the caloric fallout of not paying attention to what we’re eating doesn’t necessarily end when a meal is over.

Rose Oldham-Cooper of the University of Bristol, England, and her colleagues recruited 22 men and an equal number of women for a luncheon experiment. Each person dined alone, sequentially receiving nine small portions of food items. These ranged from cheese twists and potato chips to carrots, cherry tomatoes and sandwiches or sausage rolls.

Because the goal was to test the potential impacts of distraction on satiety, the researchers randomly assigned half of the participants to eat in front of a computer — and to rack up as many wins as possible at the “card” game solitaire. Everyone else was told to focus on the sensory attributes of their meal.

Per their instructions, the recruits ate all of the food given them. Yet people who played a computer game during lunch found their meal substantially less filling than the mindful eaters had. Game players also scarfed down twice as many cookies, almost an hour later, when they were allowed all the dessert they wanted (under the guise of a taste test). The British scientists present their findings in the February American Journal of Clinical Nutrition.

Earlier research by others had shown distraction can speed our feeding rate, potentially fostering overconsumption. So Oldham-Cooper’s team provided each participant his or her food at a precise, timed rate. The new findings can’t, therefore, be chalked up to half of the participants simply eating too fast for their bodies to gauge.

“Our findings are highly relevant to today’s society where a multitasking mentality is especially prevalent,” the authors say. Particularly troubling, they note: “One U.S. study reported that up to one-quarter of children’s total energy intake was consumed while watching television . . . [and] in a study of overweight women, almost one-half of all weekly meals were reportedly consumed in a room with a television set switched on.”

The real question is why distracted eating should impact subsequent snacking. It appears, the scientists say, that memory plays some subtle role in how we register what we eat and the degree to which it satisfies.

Interestingly, eight years ago, Britta Barkeling of Huddinge University in Stockholm and her colleagues reported somewhat related findings. Their 18 obese subjects had no choice other than to tune out everything but lunch, on one day — because they were blindfolded. Compared to a day when they could view what they were dining on, these people consumed only three quarters as many calories. Yet even hours afterward, they reported being no less sated than on the day they had been able to see their plates.

Of course dining in the dark isn’t practical. And sometimes what we eat doesn’t really invite our rapt attention. But there is certainly a growing mountain of data indicating that mindless eating is a waste of resources, a risk to our waistlines — and a costly threat to health.

Just how costly was indicated by an analysis that I ran across today (while eating at my desk, if I’m to be honest). It pegs the costs associated with obesity at 0.7 to 2.8 percent of a nation’s health care expenditures. One reason, its University of Toronto authors report in Obesity Reviews: “[O]bese individuals were found to have medical costs that were approximately 30 percent greater than their normal-weight peers.”