LOS ANGELES — Wendy's has a gluten-free menu. Dunkin' Donuts offers kosher meals at dozens of eateries. Chipotle Mexican Grill is letting customers know that it uses bacon in preparing its pinto beans.
Americans are craving more information about the food they are served, and fast-food companies, as well as casual restaurants, are increasingly obliging, many going well beyond legally mandated calorie counts.
They are updating their signs and menus for diet-conscious customers, and they also are highlighting potential problems for those with food allergies or other dietary restrictions.
Although responding to demand, quick-service restaurants also see that providing the additional information can help them stand out in the highly competitive marketplace.
"If you can demonstrate to families that you can offer them a safe meal, you establish a tremendous sense of loyalty and create repeat customers," said Chris Weiss, a vice president at the nonprofit Food Allergy & Anaphylaxis Network. "As we look to the future, we'll definitely see more restaurants doing this."
California and New York City require large chains to disclose calorie counts for each meal, and similar federal rules are coming next year.
Adding another layer of information is a natural progression, especially for restaurants eager to woo the growing number of customers who aren't eating beef burgers or can't eat food cooked in peanut oil.
Non-meat eaters rose to 8 percent of American adults in 2009 from 6.7 percent in 2006, according to the latest figures from nonprofit Vegetarian Resource Group. Food allergy cases increased 18 percent from 1997 to 2007, according to the Centers for Disease Control and Prevention.
Some diners now carry special cards listing which foods they must avoid. But following those instructions has been difficult at fast-food and fast-casual establishments, where the ingredients are often a mystery.
French fries, tortilla chips and even veggie burgers are sometimes cooked in lard or the same vats of oil used to prepare meat items. Beef flavoring or animal-derived gelatin shows up on vegetarian side dishes and salads.
It's rarely a case of intentional misinformation, said Jeanne Yacoubou, research director for the Vegetarian Resource Group.
"Should we expect restaurant staff to bend over backwards?" she said. "That's expecting a bit too much. Diners have to go a little step further to find out for sure."
Many customers, shaken by recent disclosures about food preparation, are clamoring for more specific information on signs and menus.
After non-pork eaters complained this summer, Chipotle started redesigning its menu boards to show bacon is used in its pinto beans.
Panda Express, accused in a lawsuit of using chicken powder in meat-free dishes, now says that none of its offerings is vegetarian.
Analysts said consumers over the next year will probably see a spurt in diet-sensitive menus as companies try to attract vegetarians and others with diet limitations.
"It's not that they're benevolent companies; it's that they feel that they can drive traffic by giving out more detailed information," said analyst Nick Setyan at Wedbush Securities. "It's a way to market themselves."
Wendy's is positioning itself at the forefront of the trend. Besides offering a gluten-free menu, it has posters listing all ingredients and potential allergens.
But it doesn't design meals for those with specific diets. "We have to develop products for the mass audience," spokesman Denny Lynch said.