Nutrition labels displaying calorie counts help fast food eaters cut their caloric intake, according to a new study published in the British Medical Journal.

A sample of New Yorkers was surveyed before and after the March 2008 regulation requiring fast food restaurants to post the number of calories in foods. A year later, researchers found that one in six fast food customers used the calorie information and ended up buying foods with about 106 fewer calories.

"New Yorkers who want to limit their calories are using posted calorie information to do so," said Dr. Thomas Farley, New York City Health Commissioner, in a statement. "By requiring fast food chains to post the amount of calories in food items, we've made it easier for New Yorkers to make more informed choices about the food they eat. This customer survey shows that people who are taking calorie counts into account when they order are purchasing fewer calories as a result."

Farley said posted calorie listings help consumers make healthier choices, and added that with the high rates of obesity, these types of systematic changes to the food environment are needed to fight the epidemic.

Last year, the New York City law for calorie posting was adopted nationally through the health care reform bill. It will take effect nationally within the next year, a press release from the New York city Department of Health and Mental Hygiene stated.

Obesity is a problem in every state in America, according to U.S. obesity trend data released on July 19 by the Centers for Disease Control and Prevention (CDC).

CDC's latest trend data show that the rate of obesity in the U.S. is still high and that 12 states have reported an obesity prevalence of 30 percent or higher among adults. The data is from the most recent Behavioral Risk Factor Surveillance System or BRFSS. BRFSS is a state-based phone survey that collects health information from approximately 400,000 people who are at least age 18.

The CDC's findings are similar to those included in the recent Trust for America's Health and the Robert Wood Johnson Foundation report called F as in Fat: How Obesity Threatens America's Future 2011. That report also stated that 12 states have an adult obesity rate above 30 percent. Researchers with that report also found that 16 states had an increase in the adult obesity rate over the past year.

The system of having calorie postings about food is aimed at trying to curb the obesity levels in New York, which is at an all-time high in both adults and children, according to the city's health department, as six in ten New York City adults are overweight or obese.

The leading causes of death in New York City and across the nation, according to the city's health department, are associated with obesity, including cardiovascular disease, cancer and diabetes.

A balanced, healthy diet that's high in fruits and vegetables, but low in fat and meets daily calorie recommendations can protect against these chronic diseases.

Last month, first Lady Michelle Obama unveiled the federal government's new food icon, MyPlate, to help consumers make healthier food choices. The new food icon places an emphasis on the fruit, vegetable, grains, protein and dairy food groups. The MyPlate icon replaced the MyPyramid image that previously served as the government's food group symbol.

For the New York study, researchers surveyed more than 15,000 lunchtime customers between 2007 and 2009, and reviewed their register receipts from 168 locations of the top 11 fast food chains in the city.

They found that 15 percent, or one in six customers, actually used the calorie information to make better purchases. They also found that customers at three of the major fast food chains significantly reduced the calories in the food they bought in 2009 when compared with purchases made in 2007.

Researchers found that lunchgoers at Au Bon Pain purchased 80 fewer calories; KFC customers purchased 59 fewer calories after calorie labeling went into effect; and McDonald's patrons purchased 44 fewer calories according to receipts.

These three chains together represented 42 percent of all customers in the study.

Subway, on the other hand, showed an increase in calories bought after the regulation. Subway ran a $5 foot-long sub sandwich promotion during the survey period and that resulted in a tripling of the percentage of customers who bought the 12-inch sandwich, according to a press release on the study.

Prior to the regulation, in 2007, one in four customers purchased a 12 inch sub. After the regulation and during the $5 promotion, in 2009, three in four customers purchased the 12-inch sandwich.

Data didn't show a statistically significant change in calories bought overall at all food chains.

"As calorie labeling spreads nationwide and internationally, more consumers will be able to easily access calorie information and restaurant chains will have a greater incentive to reformulate their products and offer healthier options," said Dr. Lynn Silver, a co-author of the British Medical Journal paper, said in a statement. She is also the director of the Office of Science and Policy in the health department's Division of Health Promotion and Disease Prevention.

"More complete evaluation of the long-term effects of the policy will be possible over time, but these initial findings in New York City are encouraging," Silver added. "For customers who don't examine calorie information, increasing the proportion of lower calorie offerings is important. While calorie labeling alone will not solve the obesity epidemic, it is an important tool to inform the public and provide an incentive for the restaurant industry to improve its offerings."

It is estimated that almost 50 percent of the food dollar is spent outside the home.