McDonald's, the fast food giant, announced Wednesday that it will begin posting calories on its menu boards right above customers heads in 14,000 restaurants, and at the drive-thru across the country, starting next week.

McDonald's USA President Jan Fields says after talking with customers, it's clear they want more information. "They asked us to make it easier to find nutrition information at the restaurants," she says.

The chain also will test healthier items, such as egg-white breakfast sandwiches, 350-calorie sweet chili chicken wraps and more produce side items, to add to its menu in 2013, the company said in a statement. Calorie counts will also now be clearly listed on menus inside restaurants and at drive-through windows.

The move comes ahead of a national rule that will require larger restaurant chains to make such disclosures.

Various other franchises and food chains such as Panera Bread Co. and Au Bon Pain, already post calories on their menus, but McDonald's is the largest chain and the first fast-food company to do so on a national level.

The Big Mac has 550 calories, Double Cheeseburger has 440 calories and the Southwest Salad with Crispy Chicken weighs in at 450. McDonald's highest-calorie item isn't a burger at all, but the 1,150-calorie Big breakfast with hotcakes and large biscuit. And the healthy-sounding 22-ounce mango pineapple smoothie matches the 350 calories in the grilled chicken sandwich.

The state of California and cities like New York already require that calories be clearly listed on menus. Under the new U.S. healthcare law, restaurants across the country must soon put calorie counts and other nutrition details on menus.

The national rules target restaurants with 20 or more locations, as well as other retail food outlets. Most major chains have resisted posting such information, without legislation and the threat of fines.

McDonald's plans to test foods that would increase the number of wholesome choices on its menu, including: