WASHINGTON — A bipartisan coalition of senators, restaurant chains and public health advocates reached an agreement Wednesday on legislation that would require chain restaurants to post calorie information on restaurant menus and menu boards.

The requirement, which is included in legislation introduced by Senator Edward Kennedy of Massachusetts designed to overhaul the nation’s health care system, combines key elements of the Menu Education and Labeling (MEAL) Act sponsored by Senator Tom Harkin of Iowa and the Labeling Education and Nutrition (LEAN) Act sponsored by Senators Tom Carper of Delaware and Lisa Murkowski of Alaska.

"The individual and societal costs of poor nutrition and diet-related chronic disease compel us to take concrete steps to fashion a society in which the healthy choice is the easy choice, and in which prevention always comes before treatment," Mr. Harkin said. "The menu labeling requirement reached this week will not only help consumers to make informed decisions about their health when eating out, but is a critical part of a broader reorientation to a society of prevention and health promotion."

Under the agreement, restaurants that are part of a chain with 20 or more locations would be required to list calories on their menus or menu boards. In addition, those restaurants would be required to give consumers, upon request, more nutritional information, such as fat, saturated fat, sugars, sodium, cholesterol, dietary fiber, protein and carbohydrates.

The agreement also requires the disclosure of calories for food items in vending machines owned by individuals operating 20 or more vending machines.

The proposed federal legislation comes even as a number of state and local governments have put regulations in place to require such disclosure. The restaurant industry has pushed back in most of those cases, but is among a number of industry groups on board with the latest proposal.

"We thank the senators for their bipartisan leadership and for recognizing the importance of legislation that meets the needs of both the restaurant industry and our customers," said Dawn Sweeney, president and chief executive officer of the National Restaurant Association. "We look forward to working with Congress to enact this legislation, which provides caloric information on the menu and additional information, such as sodium and carbohydrates, in other accessible formats.

"We know the importance of providing consumers with the information they want and need in a consistent format no matter where they are across the country. This legislation would replace varying state and local ordinances with a national standard that empowers consumers to make choices that are best for themselves and their families."

In addition to the N.R.A., other groups on board with the legislation include the American Diabetes Association, American Dietetic Association, The Coalition for Responsible Nutrition Information and the Rudd Center for Food Policy and Obesity at Yale University. Companies that have voiced their support for the legislation include Brinker International, Dunkin’ Donuts and Darden Restaurants.