The findings suggested that such information on the menus may increase the awareness about calorie content, but it has less of an effect in bringing about behavioral changes in line with choosing healthier food options.
Researchers based at the New York University and Yale University analyzed fast-food purchases by 1,156 adults at four fast-food chains--McDonald’s, Wendy’s, Burger King and Kentucky Fried Chicken--in poor neighborhoods of New York City where there are high rates of obesity and diabetes.
About 1100 receipts were collected from the customers twice; first two weeks before the calorie posting law took effect and then four weeks after. Each customer was paid $2 to hand over the receipt.
Number of calories purchased was higher than before
The researchers noticed that the percentage of people aware of the calorie information increased from 16 percent to 54 percent. However, they found that overall, people had, in fact, ordered slightly more calories before the law came into effect in July 2008.
They observed that only half the customers noticed the calorie counts posted on the menu boards.
Nearly 28 percent of the customers who noticed the calorie counts reported that the information had influenced their decisions to order food.
Of these, 9 out of 10 said they had made healthier choices as a result.
The researchers said, "We found that 27.7 percent who saw calorie labeling in New York said the information influenced their choices."
"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," they said further.
Expert’s views on calorie posting
The health experts noted that it was hard to change the eating behavior of the people especially the low income group who are most interested in the price than the calories.
They said that because the study was conducted only recently after the law took effect, it might not have captured changes in people’s behavior.
However, they said it was not a valid reason to abandon calorie posting on the menu boards of the fast food chains because they suspect that people's behavior will change gradually.
Brian Elbel, a professor at the New York University School of Medicine and lead author of the study, said, “Though the introduction of calorie labels did not change the number of calories purchased, a combination of public policy efforts are likely necessary to produce a meaningful change in obesity."
The study appears in the journal Health Affairs.