In 2009, King County, Wash., implemented a menu-labeling regulation that requires chain restaurants to provide calorie, saturated fat, carbohydrate, and sodium information. This study examines population-level changes in menu-labeling awareness (i.e., seeing calorie information) and use (i.e., using calorie information) before and after policy implementation in King County. Researchers analyzed 2008 through 2010 Behavioral Risk Factor Surveillance Systems data from 3,132 English-speaking King County residents ages 18 years and older who reported eating at a regulated chain restaurant. They found that after implementation of the regulation, the proportion of customers who saw and used calorie information on menus tripled (8.1% to 24.8%). White, higher-income, and obese respondents were more likely to see calorie information; and women, higher-income groups, and those eating at a fast-food chain restaurant versus a sit-down chain restaurant were more likely to use the calorie information.