WASHINGTON — Posting calorie information on restaurant menus may be influencing food choices throughout the day, according to the U.S. Department of Agriculture.

The Department discussed research pointing to benefits of the new rules a few months after federal regulations took effect requiring restaurants part of a chain of 20 or more locations nationwide to post the calorie content of all standard items on menus.

“New National Menu Labeling Provides Information Consumers Can Use To Help Manage Their Calorie Intake” was published in the Oct. 31 issue of Amber Waves. The article was written by Brandon Restrepo and Travis Minor, economists with the Economic Research Service.

The Food and Drug Administration has estimated that the new menu labeling regulations would affect 298,600 retail food establishments, organized under 2,130 chains, in the United States.

The U.S.D.A. said the requirements helped shed light on the vastly different caloric content of popular restaurant menu selections. A study found that fast-food meals (entree and one side dish) contained between 215 and 1,710 calories and full-service restaurant meals (entree and standard side dishes) contained between 219 and 2,350.

Man ordering from menu board with posted caloriesEven though the principal purpose of the regulations was to help consumers make informed eating decisions at restaurants, the Department said the information’s impact may extend to food choices and behavior throughout the day. In fact, the economists conceded that once a consumer enters a restaurant, it’s unlikely they will choose to leave if they discover menu items have higher calorie counts than desired.

“It is likely that consumers will still order food from the restaurant; however, what happens after this transaction has not largely been explored,” they said. “Perhaps, to compensate for indulging at the restaurant, individuals will have a lighter meal later in the day.”

Researchers from the E.R.S. have compared the average total daily calorie intakes of adults who saw nutrition information on a restaurant menu the last time they visited a restaurant and then used the information (“users”) to an arguably comparable group of adults, those who noticed the information but chose not to use it (“nonusers”).

“Calorie intake on a single day provides only a snapshot of consumers’ dietary behavior, so the analysis made use of an average of two self-reported, nonconsecutive, 24-hour dietary recall interviews in an effort to estimate more typical caloric intake,” the economists said. “The researchers also controlled for demographic and socioeconomic characteristics as well as interview-related factors (e.g., whether an adult’s calorie intake information refers to a weekday or weekend).”

Menu calories chartThe study was not meant to examine whether a causal relationship exists between menu label use and caloric intake. The research did show restaurant menu label users consume fewer total calories per day than do nonusers, separate from demographic and socioeconomic characteristics as well as interview-related factors.

“The E.R.S. researchers found that fast-food restaurant menu label users consumed about 180 fewer total calories per day than nonusers,” the economists said. “They also found that the total daily calorie consumption of users of menu labels in full-service restaurants was lower by about 167 calories than that of nonusers.”

The researchers also compared caloric intake of menu label users and nonusers for those eating at quick-service restaurants and full-service restaurants.

“Among adults who ate fast-food, those who used fast-food menu labels consumed fewer calories than did nonusers from fast-food restaurants; grocery stores, supermarkets, and other food retailers; and food-away-from-home places other than fast-food and full-service restaurants,” the economists said. “And among adults who ate food from a full-service restaurant, those who used full-service restaurant menu labels consumed fewer calories than did nonusers from full-service restaurants, fast-food restaurants, and other food-away-from-home places. These results suggest that the total daily energy intake gaps between menu label users and nonusers arise not only from food choices made in the restaurants that post nutrition information on menus but also from decisions made in grocery stores and supermarkets, as well as in other eateries that may not have had point-of-purchase nutrition information available.”