Ashlei James, from Texas Christian University, in Fort Worth, and colleagues randomly assigned 300 men and women (aged 18 to 30 years) to a menu without calorie labels (NCL; 99 participants), a menu with calorie labels (CL; 99), or a menu with labels on the minutes of brisk walking needed to burn the food calories (EL; 102). The same food/beverage options were listed on all menus.
The researchers observed a significant menu effect on both calories ordered and consumed. In the EL group compared to NCL group there were significantly fewer calories ordered (adjusted mean, 763 versus 902 kcal) and consumed (adjusted mean, 673 versus 770 kcal). The CL and the NCL groups did not differ significantly in the food calories ordered or consumed. Similarly, there was no difference between the CL and the EL groups. Post-lunch calorie intake did not differ by menu condition.
"This study suggests there are benefits to displaying exercise minutes to a group of young men and women. We can't generalize to a population over age 30, so we will further investigate this in an older and more diverse group," a coauthor said in a statement. "This is the first study to look at the effects of displaying minutes of brisk walking needed to burn food calories on the calories ordered and consumed."