Why dieting SUCKS, as told by NY Times

Health Halo Can Hide the Calories, By JOHN TIERNEY
Published: December 1, 2008

I offer this alibi after an experiment on New Yorkers that I conducted with Pierre Chandon, a Frenchman who has been studying what researchers call the American obesity paradox. Why, as Americans have paid more and more attention to eating healthily, have we kept getting fatter and fatter?

Dr. Chandon’s answer, is that Americans have been seduced into overeating by the so-called health halo associated with certain foods and restaurants.

Our collaboration began Brooklyn’s Park Slope, whose celebrated food co-op has a mission statement to sell “organic, minimally processed and healthful foods.”
Half of the 40 people surveyed were shown pictures of a meal consisting of an Applebee’s Oriental Chicken Salad and a 20-ounce cup of regular Pepsi. On average, they estimated that the meal contained 1,011 calories, which was a little high. The meal actually contained 934 calories — 714 from the salad and 220 from the drink.

The other half of the Park Slopers were shown the same salad and drink plus two Fortt’s crackers prominently labeled “Trans Fat Free.” The crackers added 100 calories to the meal, bringing it to 1,034 calories, but their presence skewed people’s estimates in the opposite direction. The average estimate for the whole meal was only 835 calories — 199 calories less than the actual calorie count, and 176 calories less than the average estimate by the other group for the same meal without crackers.

Just as Dr. Chandon had predicted, the trans-fat-free label on the crackers seemed to imbue them with a health halo that magically subtracted calories from the rest of the meal. And we got an idea of the source of this halo after I tried the same experiment with tourists in Times Square.

These tourists, many of them foreigners (they kept apologizing for not knowing what Applebee’s was), correctly estimated that the meal with crackers had more calories than the meal without crackers. They didn’t see the crackers’ health halo, Dr. Chandon said, presumably because they hadn’t been exposed to the public debate that accompanied New York City’s decision last year to ban trans fat from restaurants.

“It makes sense that New Yorkers would be more biased because of all the fuss in the city about trans fat,” Dr. Chandon told me. “It hasn’t been a big issue in most other places. Here in Europe there’s been virtually no discussion of banning trans fats.”

The researchers found that customers at McDonald’s were more accurate at estimating the calories in their meal than were customers at Subway, apparently because of the health halo created by advertisements like one showing that a Subway sandwich had a third the fat of a Big Mac. The health halo from Subway also affected what else people chose to eat, Dr. Chandon and Dr. Wansink reported last year after giving people a chance to order either a Big Mac or a 12-inch Italian sandwich from Subway. Even though the Subway sandwich had more calories than the Big Mac, the people ordering it were more likely to add a large nondiet soda and cookies to the order. So while they may have felt virtuous, they ended up with meals averaging 56 percent more calories than the meals ordered from McDonald’s.

“People who eat at McDonald’s know their sins,” Dr. Chandon said, “but people at Subway think that a 1,000-calorie sandwich has only 500 calories.” His advice is not for people to avoid Subway or low-fat snacks, but to take health halos into account.