WASHINGTON — The Food and Drug Administration will announce sweeping rules Tuesday that will require chain restaurants, movie theaters, and pizza parlors across the country to post calorie counts on their menus. Health experts said the new requirements will help combat the country’s obesity epidemic by showing Americans just how many calories lurk in their favorite foods.  The rules will have broad implications for public health. As much as a third of the calories Americans consume come from outside the home, and many health experts believe that increasingly large portion sizes and unhealthy ingredients have been significant contributors to US obesity.  “This is one of the most important public health nutrition policies ever to be passed nationally,” said Margo Wootan, director of nutrition policy at the Center for Science in the Public Interest. “Right now, you are totally guessing at what you are getting. This rule will change that.”  The rules are far broader than consumer health advocates had expected, covering food in vending machines and amusement parks, as well as certain prepared foods in supermarkets. It applies to food establishments with 20 or more outlets, including fast-food chains like KFC and Subway and sit-down restaurants like Applebee’s and Cheesecake Factory.  Perhaps the most surprising element of the new rules was the inclusion of alcoholic beverages, which had not been part of an earlier proposal. Beverages served in food establishments that are on menus and menu boards will be included, but a mixed drink at a bar will not, FDA officials said.  “It’s much tougher than the original,” said Marion Nestle, a professor in the department of nutrition, food studies, and public health at New York University. “I’m amazed. It never occurred to me that alcohol would make it in.”  The new rules will take effect a year from now and seem likely to face legal and political challenges from some parts of the food industry, including grocery and convenience stores that sell prepared foods for takeout.  Menu labeling became law in 2010 as part of the Affordable Care Act, and the FDA issued a proposal for how it should be implemented the following year. But the final rules were delayed for three years, in part because of opposition from pizza and movie theater chains.  The release of the rules just weeks after the midterm elections prompted some advocates to suggest that politics may help explain the rules’ timing and toughness. The administration backed away from covering movie theaters in 2011, the year before the last presidential election, when the Obama administration was keen to avoid giving Republicans ammunition for the charge that it was too quick to impose unnecessary and costly regulations.  The rules apply to prepared foods sold in groceries and convenience stores that are intended to feed one person, such as a sandwich or a salad, but not to bulk items like loaves of bread or a rotisserie chicken.  The FDA allowed journalists to view an abbreviated description of the rules, but they will not be published officially until Tuesday, and most industry groups had yet to see the details.  Trade associations like the National Automatic Merchandising Association, which represents vending machine operators, and the National Grocers Association said they could not comment on the new rules without seeing them. Lyle Beckwith, senior vice president for government relations at the National Association of Convenience Stores, said that he feared his members were being subjected to a regulatory regime that was never intended to include them.
Counting your calories will become easier under new government rules requiring chain restaurants, supermarkets, convenience stores — and even movie theaters, amusement parks and vending machines — to post the calorie content of food ‘‘clearly and conspicuously’’ on their menus.