The Center for Disease Control calls the obesity problem in the U.S. an “epidemic.” Around 72 Million adult Americans are obese, which is equivalent to one third of the total population. Because of the strong link between fast-food consumption and obesity, one measure to fight obesity is calorie labeling (menu labeling) at fast-food restaurants.

A legislation requiring restaurants to visibly post the caloric content of all regular menu items was passed in New York City in 2008, making it the first U.S. jurisdiction to pass such legislation. More than thirty other American cities or states have introduced similar legislation since, with thirteen of the bills becoming laws.

However, a study published this month in the journal Health Affairs has shown that the introduction of calorie labeling does not affect calories purchased, i.e., eating habits. The researchers conducted the study at fast-food chains (McDonald’s, Burger King, Wendy’s and KFC) in New York City and in Newark (a control city, where there is no calorie labeling). In both cities, the researchers chose low-income demographic areas with mostly minority groups.

Before calorie labeling was introduced, people in New York City purchased around 825 calories on average per meal. Surprisingly, that number increased slightly to 846 after labeling was introduced. In Newark, where no change in labeling happened, average number of calories purchased per meal remained between 823 and 826. Moreover, customers in both cities did not change their purchase of food rich in saturated fats, sodium or sugar, even after labeling of these items was included.

Based on evidence from this study, it is obvious that eating behavior is very resistant to change. While displaying caloric values of various food items and meals might create awareness among customers, it certainly fails to affect their behavior to make healthier food decisions. Other obesity-related policies (such as taxes on sugary beverages) might prove to be more effective in preventing and reducing obesity.