Dr. James W. Krieger of the Public Health -- Seattle & King County and colleagues evaluated the impact of Washington State's King County's menu-labeling regulation six and 18 months after it went into effect. In 2009, King County became the second jurisdiction in the nation to implement a menu-labeling law.
The study, published in the American Journal of Preventive Medicine, found after 18 months, the average calories per purchase at chain restaurants fell by 38 calories, from 908.5 calories to 870.4, regardless of whether customers reported seeing or using the calorie information.
One-third of customers reported using calorie information to guide their purchases and the impact was greatest among this group -- an average decrease of 143 calories per purchase, the study said.
The researchers surveyed more than 7,300 patrons ages 14 and older at 10 restaurant chains, including Subway, McDonalds, Taco Bell, Starbucks, and other local chain restaurants before the law took effect, and again six and 18 months after implementation.
"Menu labeling is critical because Americans spend nearly half of their food dollars on foods prepared outside the home, which tend to be higher in calories and less healthy than what we eat at home," Krieger said in a statement. "Over time, people seem to respond to the availability of information and use it to inform their purchases."