In an action likely to rock the fast-food industry, McDonald's Wednesday said it will post calories for all items on its menu boards and drive-thru menus in the U.S.

The move by the world's largest fast-food chain comes as consumers, regulators and activists are pressuring the industry to improve food quality and share more nutritional information with consumers.

As the fast-food behemoth, McDonald's gets the most attention and criticism for its actions, and the rest of the industry often follows its lead. Industry rivals are expected to quickly follow McDonald's menu changes, which start next week.

"It's the right thing to do," says Greg Watson, senior vice president of menu innovation for McDonald's. "It's what a leader would do."

Other factors are also in play. President Obama's health care reform includes a proposed regulation still under review by the Food and Drug Administration that would require many chain restaurants to post calories on menus and menu boards. But no one expects any action on that front until well after the presidential election.

"It's an important step forward," says Michael Jacobson, executive director of the advocacy group Center For Science in the Public Interest, which has been a long-time critic of McDonald's. "The other fast-food chains will feel the competitive pressure to provide the same information."

McDonald's has been a leader, but a "reluctant" leader on several nutritional fronts in recent years, Jacobson says. The company was among the first major chains to knock the trans fat out of its french fries. It was among the first to put fruit into kids' meals. And it was early to offer an array of salads.

Panera was the first major chain to post calories on menu boards back in April 2010. "We knew that posting calories on our menu boards could only help us because it helped our guests," says founder Ron Shaich.

Not everyone is applauding.

"They fought and fought and fought against this, and now they act like they wanted it all the time," says Kelly Brownell, director of the Rudd Center for Food Policy & Obesity at Yale University.

Not so, says McDonald's spokeswoman Danya Proud, who insists that McDonald's supported a clear, federal regulation but objected to all of the different local regulations in places like New York City and Southern California.

McDonald's isn't stopping here, either, says Watson. It plans more seasonal fruit and veggie options, such as blueberries and cucumbers. And it's testing an egg-white breakfast sandwich on a whole grain English muffin.

USA Today