Excess body weight is a risk factor for a range of chronic diseases. Currently, more than two thirds of US adults are obese or overweight, with increasing rates of childhood obesity. The medical costs of overweight and obesity have been estimated at $169 billion per year, and even modest population-level reductions in calorie intake of 100 calories per day could save as much as $58 billion. Increasing calorie intake "outside the home" at fast-food and other restaurants has contributed to the rise in obesity. In 2013, the US will become the first country in the world to implement federal regulations requiring nutritional labeling on menus. The regulations mandate that calorie amounts appear on menus next to the price and that additional nutrient information be made available at the point-of-sale. The regulations will apply to chains of 20 or more restaurants, which account for the vast majority of restaurant visits in the US. The federal menu labeling regulations will establish a new international precedent and are among the most significant policy interventions in nutrition education since mandated nutrition information on pre-packaged foods. Six US states and several cities have already implemented similar policies. The primary objective of the current study is to examine the population level impact of nutritional information on menus on dietary patterns using a "pre-post" quasi- experimental design in which "baseline" and "follow-up" measures will be conducted in the US and Canada, which will serve as the control group given that no regulations have been implemented or are planned. The study will consist of nationally representative phone surveys at pre and post, and face-to-face exit surveys of restaurant patrons at pre and post. First, population-based telephone surveys will be conducted with representative samples of 1,000 participants in both jurisdictions before and after the implementation of the federal menu regulations, scheduled for late 2012, early 2013. Exit surveys will also be conducted with 1,000 participants before and after implementation in each of four paired cities: Seattle-Vancouver, and Chicago- Toronto. Seattle is among the US jurisdictions that have previously implemented menu labeling regulations. Exit Surveys will be conducted with patrons of 5 "full service" and 5 fast-food restaurants at two locations in each city. The representative phone surveys and Exit Surveys will be conducted during the same period (before and 12 months after implementation) using parallel measures to assess the extent to which the data from Exit Surveys can be generalized to the population level. Note that baseline data collection has already been conducted: funding is requested for follow-up data collection only. Overall, the current study has the potential to make important contributions to the evidence base on nutritional labeling and to evaluate a novel policy measure for preventing obesity. The study will help to establish whether requiring nutritional information on restaurant menus modifies intake, including whether the effects may differ among sub-populations.