LOS ANGELES — A calorie-labeling intervention did not result in a significant decrease of meal calorie content or improve estimation at McDonald's, a speaker said here at ObesityWeek 2015.
Jason Block, MD, MPH, Harvard Medical School, and colleagues conducted a study to "quantify whether calorie menu labeling was associated with a reduction in meal calorie content and also whether it led to an improvement in calorie estimation," he said.
They also assessed whether consumers reported an increase in calorie information use due to menu labeling.
"There have been a number of studies about this topic and we'll learn more as the federal law will actually be implemented next year, Dec. 1, 2016, but overall, this literature is mixed," Block said. "Real world studies that have been conducted in restaurants themselves have mostly been null, not finding much of an effect on the calorie content of meals. Laboratory studies have gone in both directions."
In general, he said, studies have shown that labeling leads to increased self-reported use and recognition of calories.
Block and colleagues evaluated McDonald's voluntary calorie labeling initiative, which began in September 2012. They compared the fast food chain to five other chains — Subway, Burger King, Wendy's, KFC and Dunkin Donuts — which did not post their calories. The investigation took place at approximately 80 restaurants in four New England cities.
The researchers approached customers in parking lots and asked them to keep their receipts. When customers exited the restaurants, they shared their receipts, took short surveys, estimated the calorie count of their meal and reported whether they saw calories, Block said.
Baseline visits were conducted in 2010 and 2011 and follow-up visits were conducted in 2013 and 2014 after McDonald's calorie labeling intervention. Block and colleagues used bivariate comparisons to analyze differences in meal calories, accuracy of calorie estimates, and the recognition and use of calorie information pre- vs. postlabeling at McDonald's and other chains. Analysis included 606 adults and 524 adolescents at McDonald's and 1,271 adults and 654 adolescents at other chains prelabeling and 356 adults and 343 adolescents at McDonald's and 795 adults and 564 adolescents at other chains postlabeling.
Results showed that, in adults aged 18 years and older, calorie content decreased from 721 kcal to 638 kcal at McDonald's (P < .01) and from 892 kcal to 817 kcal at other chains (P < .01) pre- vs. post-labeling, respectively. In adolescents aged between 11 and 20 years, calorie content decreased from 763 kcal to 704 kcal at McDonald's (P = .05) and from 751 kcal to 744 kcal at other chains (P = .8) pre- vs. postlabeling, respectively.
Consumers did recognize calories more at McDonald's postlabeling, Block said, which was not true of the other chains. About 50% of the adults reported seeing calories, but use of calories was less than 15%.
There was no change in the accuracy of calorie estimation in either adults or adolescents.
"We see the secular trends at least among adults in calorie reduction," Block concluded. "These may be following in parallel with menu labeling. All of these restaurants know that menu labeling is coming and they may be preparing for it, which is why we see some reduction across the board. But there's no clear evidence, at least in our study, that menu labeling is directly reducing calories purchased or improving estimation." – by Chelsea Frajerman Pardes and Joan-Marie Stiglich, ELS
Block J. Evaluating the Effect of Posting Calories on McDonald’s Menus: A Controlled Natural Experiment. Presented at: ObesityWeek; Nov. 2-6, 2015; Los Angeles.
Disclosures: The authors report no relevant financial disclosures.