New research suggests that putting up menu calorie counts in chain restaurants may be ineffective, Yahoo News reported.

Researchers at New York University's Langone Medical Center found that calorie labels, on their own, have not reduced the overall number of calories that consumers of fast food order and presumably eat. The study offers early evidence of its possible impact as the federal government prepares to introduce the policy nationwide in December 2016 as part of its Affordable Care Act.

"Our study suggests that menu labeling, in particular at fast-food restaurants, will not on its own lead to any lasting reductions in calories consumed," Brian Elbel, senior investigator of the study, said in a statement.

For the study, researchers collected and analyzed data from nearly 7,700 fast-food diners in New York City and nearby New Jersey cities, HealthDay reported. They compared food orders in places with and without calorie counts.

Researchers found that the average number of calories bought by patrons at each sitting between January 2013 and June 2014 was statistically the same as those in a similar survey of 1,068 fast-food diners in 2008, when New York City initially imposed menu labeling. Diners were surveyed at major fast-food chains: McDonald's, Burger King, KFC, and Wendy's.

Calorie counts in the 2013-2014 analysis averaged between 804 and 839 per meal at menu-labeled restaurants, and between 802 and 857 per meal at non-labeled eateries; whereas, they averaged 783 per meal for labeled restaurants and 756 per meal for non-labeled restaurants shortly after the policy was introduced.

However, Elbel said there is still cause for optimism, because the current and previous studies show at least some awareness of the bloated calorie counts in most fast food.

"People are at least reading the information, some are even using it," he said.

However, the number of people paying attention to the calorie counts diminishes over time. Elbel notes that at the start of the 2013 study, 45 percent of survey respondents said they noticed the calorie counts, a decrease from 2008 levels. As the study continued, this number dropped six months later to 41 percent and dropped again in 2014, to 37 percent, in the last set of surveys.

An estimated third of adult Americans are obese (with a body mass index of 30 or more), and that number is expected to rise to 42 percent by 2030, among the highest of any country in the developed world,

The findings are detailed in the journal Health Affairs.