A new study showed calorie counters next to McDonald's menu items have not promoted healthy eating habits, CBS News reported.

The study, published Thursday in The American Journal of Public Health, showed that any restaurant displaying the number of calories next to the menu item did not cause Americans to eat healthier.

Several states already require their chain restaurants to have such a calorie counter and Congress has passed legislation to develop a national calorie labeling system to aid in health care reform. The study shows that calorie counts do not discourage Americans from eating fast food about two times a week.

"The general inability of calorie labeling to result in an overall reduction in the number of calories consumed has already been pretty widely shown," study author Julie Downs, an associate research professor of social and decision sciences in the Dietrich College of Humanities and Social Sciences at Carnegie Mellon University, told HealthDay. "So that's nothing new. But in the face of that, there has been the growing thought that perhaps the problem is that people don't know how to use the information without some framework, some guidance."

The researchers had 1,904 consumers aged 18 and older eat at two New York McDonald's locations, since New York is mandated to post calorie counts. A third of the consumers were given a flyer stating the healthy amount of calories in a day for men was 2,400 and 2,000 for women. A third were given flyers that stated a single meal should contain anywhere from 650 to 800 calories. The last third was not given anything at all.

The researchers looked at the consumers' receipts after they ordered and had participants fill out a post-meal survey.

The team found that even those with the informational brochures did not consider the daily or meal recommendations for calories. They found that men ordered 11 percent more than what was advised for a meal and women averaged 27 percent over.

"In the end the bigger issue is that asking people to do math three times a day every day of their lives is a lot," Downs added. "Because it's not like we make a decision about what to eat just once. It's a lot of decisions. And if you add a cognitive [mental] burden on top of that it's a lot to ask."

(The author of this article changed the incorrect figure of "2,00" calories a day for women to 2,000.)