As prominent pediatrician Andrew Carroll noted in the New York Times last week, a once-promising behavioral nudge—placing calorie counts on restaurant menus, in an attempt to get diners to choose healthier options—is, to date, a clear failure.
Five years after New York City mandated that calorie information be posted on the menus of fast-food chains, a recently published study found no significant reduction in the amount of calories consumed. A separate meta-study, published last year, reported that, in six studies conducted in real-life restaurants, such labeling produced a "nonsignificant" reduction in caloric intake.
While this isn't good news—and doesn't bode well for the new excess-salt warnings added to menus this week—public health advocates needn't give up just yet. Another new study finds calorie listings can indeed influence diners' choices—but only under very specific circumstances.
It appears that restaurants' pricing policies is a key to making calorie counts work.
Kelly Haws of Vanderbilt University and Peggy Liu of Duke University report that, when restaurants offer both full-size and half-size portions of entrées, and calories for each are listed on the menu, a significant number of people will check both out, and then choose a different, healthier entrée.
There is a rub, however (and we're not talking about the preparation of your steak). This surprising—but explainable—dynamic only occurs when full-size and half-sized meals are proportionately priced. When a larger order is available for only a little more money, most diners are not able to resist going for the bargain—even if it will expand their waistlines.
"There may be something particular about including half portions under a linear pricing scheme that leads consumers to respond to calorie information by choosing healthier full portions," the researchers write in the journal Appetite.
Their main study featured 245 American adults recruited online via Amazon's Mechanical Turk. Participants examined a restaurant-style menu featuring 10 different entrées (five healthy, and five less-healthy) in two sizes (full and half).
Approximately half of the menus listed calories of the items, while the others did not. Pricing also varied: On half the menus, the larger items were relatively less expensive than the smaller ones.
Public health officials hoped that calorie information would prompt people to go for the smaller portion. The researchers found this generally did not happen.
But a different, equally welcome dynamic unfolded: Many diners looked at their two options and then went for a third—a larger portion of a healthier entrée. They wanted the best of both worlds (low calories and a big portion), and they found it.
Unfortunately, the researchers report this only occurred when the price of the larger entrée was proportionately priced (that is, a 50 percent larger entrée cost approximately 50 percent more). When the larger dish was priced as a bargain, they write, "calorie information has no impact on calories selected."
Haws and Liu explain this by reminding us that, in general, "consumers try to seek out more easily justified options." They note that it is easy to "justifying sticking with a full portion of one's preferred unhealthy entrée when it is cheaper per unit," even when you are fully aware of its down side.
On the other hand, when the bigger and smaller portions are proportionately priced, and the calorie information makes it clear that the smaller one is the smarter choice, it becomes difficult to justify going with the mega-meal. "One available solution" to this quandary, they write, is to look further down the menu and choose a large portion of a healthier meal.
This research suggests calorie listings do inspire diners to take health costs into consideration when choosing their meal. However, economic costs also play a major role in their decision-making.
So it appears that restaurants' pricing policies is a key to making calorie counts work. Many large chains decided long ago to encourage the purchase of large portions by making them attractively priced. Until they re-think that strategy, calorie information on menus appears to be of limited value at best.
Findings is a daily column by Pacific Standard staff writer Tom Jacobs, who scours the psychological-research journals to discover new insights into human behavior, ranging from the origins of our political beliefs to the cultivation of creativity.