Chain restaurants across the country are being required to place the calorie counts of the food they serve in their menus in an attempt to curb the obesity problem in the U.S., but does this really affect the way people order their food?

A new study which was published in the American Journal of Public Health on Jan. 20 suggests that in Seattle area, diners actually pay attention to these calories postings and that the number of people who use this information has grown threefold since posting the calories counts on restaurant menus became mandatory in the area.

Results of the study were based on telephone surveys of over 3,000 frequent restaurant diners in Washington State's King County, which also includes Seattle city. It covered from eight months prior to when restaurants in the county were obliged to post the calorie information on their menu, in January 2009, until two years after.

The survey revealed that women, patrons of fast-food chains, partnered or married individuals and high-income diners in the Seattle area were more likely to use the calorie-count information compared with other individuals, suggesting that such disclosure may actually help influence people's dining habits.

"It was a confirmation that if you post calorie information, more people are going to see it and more people are going to use it," said study author Roxana Chen, a social research scientist at the county's public health office.

Although many diners do not yet take advantage of the calorie information, the survey shows that the number of people who do has grown over a three-year period.

Between the mid-2008 and December 2010, the researchers found that the number of people who claimed to read the calorie information in restaurants has grown from a mere 18.6 percent to 59.4 percent. The number of those who used this calorie information to decide on what food to order likewise increased from only 8.1 percent to 24.8 percent.

"Significant increases in calorie information awareness and use following regulation support the population-wide value of this policy," the researchers wrote. "However, improvements varied across race, income, and gender."

The researchers said that the disparities among different groups were not surprising. They pointed out the results highlight the importance of researchers and public health officials focusing on how to best inform the groups that seem not interested in restaurant calorie information, such as those with limited knowledge on nutrition, minority populations and those with less money to spend.