A new study shows that people tend to underestimate the calories in fast-food items that they consider relatively healthy.
Those diners, perhaps thinking they've got a little leeway in their calorie budget, often treat themselves to cookies, sodas, or other extras that push their calories even higher.
That's according to Pierre Chandon, Ph.D., and Brian Wansink, Ph.D. Chandon is an associate professor of marketing at the European Institute for Business Administration (INSEAD), a business school in Fontainebleau, France. Wansink is the John S. Dyson Chair of marketing and of nutritional science in Cornell University's applied economics and management department. Their report on fast-food health claims appears in October's edition of the Journal of Consumer Research.
Chandon and Wansink conducted several fast-food experiments.
First, they compared the calorie expectations of people eating at Subway and McDonald's. The researchers argue that Subway touts the healthiness of its food while McDonald's doesn't.
For instance, Chandon and Wansink asked people eating a sandwich, soft drink, and a side order from Subway or from McDonald's how many calories they thought those meals contained.
The meals actually had the same number of calories. In this experiment, the diners didn't know how many calories they were getting in their meals, though McDonald's and Subway post their nutritional information on their Web sites.
The Subway diners thought their meal had 151 calories less than it actually had - a 21% underestimation.
Chandon and Wansink also offered 46 undergraduates a coupon for a Subway 12-inch Italian BMT sandwich or a McDonald's Big Mac.
When asked what they wanted with their sandwich, the Subway diners were more likely to pick high-calorie side orders. Perhaps they thought their sandwich was a caloric bargain (even though it actually had 900 calories, compared with the 600-calorie Big Mac), the researchers suggest.
The researchers stress that they're not trying to slam Subway or promote McDonald's. They didn't do an in-depth nutritional analysis of every item on those restaurants' menus.
In their final experiment, Chandon and Wansink made up two imaginary restaurants - "Good Karma Healthy Foods" and "Jim's Hearty Sandwiches."
The researchers presented 214 university students with menus from both restaurants. The "Good Karma Healthy Foods" menu included carrot soup and organic hummus, while "Jim's Hearty Sandwiches" had fattier fare, such as sausage sandwiches.
After reading those pretend menus, the students saw identical sandwiches and drinks labeled with one or the other imaginary restaurant's name.
The students estimated that the sandwich from the "healthier" restaurant had fewer calories - but when the researchers challenged that assumption, they weren't quite so sure about that.
The researchers aren't against splurging on calories every now and then.
"There is nothing wrong with occasionally enjoying a high-calorie meal as long as people recognize that they have had a lot of calories and that they need to adjust their future calorie intake or expenditure accordingly," they write.
But Chandon's and Wansink's point is not to rely too much on the assumption that "healthy" menu items are lower in calories.
By Miranda Hitti
Reviewed by Louise Chang
(C)2007 WebMD, Inc. All rights reserved