The implementation of a new California law on January 1, 2011, will require chain restaurants to label calories on menus. This study will test the hypothesis that restaurants subject to a calorie labeling law are more likely to improve the caloric and nutritional content of menu items, compared to restaurants not subject to the law. The study aims to: 1) describe the current food environment in restaurants, including how restaurant characteristics and state/local policies are associated with menu nutrition, and 2) evaluate changes in calorie levels of restaurant menus between 2010 and 2011 – that is, before and after full implementation of the California law. The study will compare a treatment group (chain restaurants subject to the law – that is, with 20 or more locations in California) with a control group (chain restaurants not subject to the law). It will compare self-reported caloric and nutritional data for standard menus that are made available by restaurants on their websites or upon request, between spring 2010 and spring 2011; baseline data were previously collected. Overall, this study will help to provide policy-makers with a better understanding of the full effects of regulatory disclosure policies on public health.