Variyam and Cawley's study, published in 2006 by the National Bureau of Economic Research, found that nutrition labeling did reduce obesity but only among a single demographic: white, non-Hispanic women. For all other demographics—Hispanic and black women and men of every ethnic group—they found no significant impact after nutrition labeling became required.
Will menu labeling be any more effective? Slate's New York reporting (see video on previous page) indicated that most fast-food patrons said it wouldn't affect their meals. For some people, the question is moot. Julia Patterson is the chairwoman of the board of health in King County, Wash., where menu labeling will go into effect on Jan. 1. Asked whether King County had studied the link between menu labeling and obesity, Patterson rejected the very premise.
"When we made the decision to warn people about the fact that cigarettes can cause cancer on a pack of cigarettes," she said, "nobody demanded that a study be done to determine whether or not that information would have an impact on smoking habits of Americans."
Actually, the example of cigarette labeling is cause for more studies, not fewer. The Surgeon General began putting warning labels on cigarette packs in 1965. Sixteen years later, the Federal Trade Commission found that fewer than 3 percent of adults even read the labels, leading Congress to pass the Comprehensive Smoking Education Act in 1984, making the warning labels more explicit. Meanwhile, ineffective warning labels had been used for nearly two decades. That message isn't lost on the people running New York City's menu-labeling program. Cathy Nonas, director of physical activity and nutrition programs for the city's health department, said the city will use its earlier study as a base line, then commission a similar study after the regulation goes into effect.
The restaurant industry isn't waiting for the numbers to come in. "They have absolutely no scientific backup for any of their claims," said Chuck Hunt, executive vice president of the New York State Restaurant Association, which claims the menu-labeling law violates the First Amendment and is suing to have the law struck down. Hunt said more-prominent calorie information won't change enough people's decisions to make a difference. "I don't care if you stamp it on their foreheads, some people are not going to pay attention to it."
Hunt may have a credibility issue when it comes to public-health legislation: He's the same person who claimed, in 2002, that a smoking ban in New York restaurants would cause business to decline drastically—in fact, business went up.
The law may have the salutary effect of getting restaurants to change their ways. Nonas uses the example of Starbucks, which has reacted to the debate over menu labeling by switching its default milk from whole to 2 percent. Margo Wootan, director of nutrition policy for the Center for Science in the Public Interest, said getting restaurants to change what they serve can be just as important as getting customers to change what they order. "Maybe McDonald's will rethink whether a large shake really needs to have 1,200 calories," she said. "Could people be happy with a 900-calorie shake?"
The calorie rule is an example of informing everyone in the hopes that they will make healthier choices, which is hard to oppose in principle. So, perhaps everyone wins. Yet the absence of unbiased opponents of menu labeling means that lost in the debate over Big Macs and cheesecake has been any serious consideration of whether government agencies ought to be responsible for influencing how many calories we eat.
This summer's outbreak of salmonella in tomatoes, which has made more than 800 people sick nationwide, suggests that government's culinary hyperfocus would be better trained elsewhere. Regardless, it's a strange moment in the history of American municipal government: Banning the sale of most handguns—which undeniably kill thousands of people a year—is prohibited, but it's OK to tell McDonald's how to run its business, based on a plausible but scarcely proven theory of human behavior.