Despite the lack of any concrete evidence that menu labels encourage consumers to make healthier food choices, they have become a popular tool for policymakers in the fight against obesity.

Carnegie Mellon University researchers recently put menu labels to the test by investigating whether providing diners with recommended calorie intake information along with the menu items caloric content would improve their food choices. The study, published in the American Journal of Public Health, showed that recommended calorie intake information did not help consumers use more effectively.

"There have been high hopes that menu labeling could be a key tool to help combat high obesity levels in this country, and many people do appreciate having that information available. Unfortunately, this approach doesn't appear to be helping to reduce consumption very much, even when we give consumers what thought might help: some guidance for how many calories they should be eating," said the study's lead author Julie Downs, associate research professor of social and decision sciences in CMU's Dietrich College of Humanities and Social Sciences.

For the study, Downs and the research team analyzed the purchase behaviors of 1,121 adult lunchtime diners at two McDonald's restaurants in New York City. To explore the potential interaction between pre-existing menu labeling and the addition of recommended calorie intake information, three groups of diners received different information: (1) recommended ; (2) recommended per-meal ; and (3) no additional information. Survey data also was gathered to capture the diners' understanding of .

The results showed no interaction between the use of calorie recommendations and the pre-existing menu labels, suggesting that incorporating calorie recommendations did not help customers make better use of the information provided on calorie-labeled menus. Further, providing calorie recommendations, whether calories per-day or per-meal, did not show a reduction in the number of calories purchased.

"People who count calories know that this is a pretty labor-intensive exercise," Downs said. "Making the information available on menus may have other beneficial effects, such as motivating restaurants to change their formulations. But it may be unrealistic to expect many consumers to keep such close, numeric track of their food intake by using the labels directly."