The research by a team from New York University and Yale University, which was published Tuesday in Health Affairs, suggests some people actually ordered slightly more calories than before the July 2008 law took effect.
New York was the first US city to impose the calorie law, which is meant to promote healthier eating and combat the national obesity epidemic.
According to the survey, only half of 1,156 low-income, fast food consumers noticed the calorie count, and just over a quarter of those who did actually based their decisions on the information.
"We found that 27.7 percent who saw calorie labeling in New York said the information influenced their choices," the researchers wrote.
"However, we did not detect a change in calories purchased after the introduction of calorie labeling. We encourage more research on menu labeling and greater attention to evaluating and implementing other obesity-related policies."