Why healthy can make us fat

Brian Wansink, author of Mindless Eating: Why we eat more than we think (see yesterday's Heart Scan Blog post), also has a Blog. Despite the bland advice offered on much of the Prevention Magazine and website, Wansink's Food Think Blog is a winner.

In a recent post, Wansink quotes a report from Science Daily that described a study he recently published in the Journal of Consumer Research. Wansink's study describes how just applying the label "healthy" to fast food choices increased consumers' calorie intake:

"When we see a fast-food restaurant like Subway advertising its low-calorie sandwiches, we think, 'It's OK: I can eat a sandwich there and then have a high-calorie dessert,' when, in fact, some Subway sandwiches contain more calories than a Big Mac."

In one study, Chandon and Wansink had consumers guess how many calories are in sandwiches from two restaurants. They estimated that sandwiches contain 35% fewer calories when they come from restaurants claiming to be healthy than when they are from restaurants not making this claim.

The result of this calorie underestimation? Consumers then chose beverages, side dishes, and desserts containing up to 131% more calories when the main course was positioned as "healthy" compared to when it was not--even though, in the study, the "healthy" main course already contained 50% more calories than the "unhealthy" one.

"These studies help explain why the success of fast-food restaurants serving lower-calorie foods has not led to the expected reduction in total calorie intake and in obesity rates," the authors write.

Interesting. In fact, I've had many patients say that they eat at Subway or similar chains and choose the "healthy" options. "That's got to be better than a cheeseburger and fries!" Perhaps not. (Of course, you can't leave Subway or other fast food operation feasting on wheat products.)

Wansink can be counted on for some truly fascinating observations into many behaviors that are subconscious but explain at least part of the reason why we're so fat. Though his Blog has a relatively short history of posts, there's lots of great commentary.

Pierre Chandon and Brian Wansink. "The Biasing Health Halos of Fast Food Restaurant Health Claims: Lower Calorie Estimates and Higher Side-Dish Consumption Intentions" Journal of Consumer Research, October 2007.