A coalition of consumer groups said yesterday that fast-food restaurants should label ingredients in their products.

The consumer groups are petitioning the government to require fast-food companies to disclose the ingredients they use in their products just as food companies that sell packaged and labeled products must do. According to the consumer groups, the labeling already is required by law, but the restaurant industry says it is not.

Consumers concerned about allergies, worried about fat and salt or seeking to follow other dietary restriction need to know what is in the foods they buy, and ingredient labels should be required to inform them, said Michael F. Jacobson, executive director of the Center for Science in the Public Interest, one of the consumer groups that have petitioned the government.

Joining Jacobson in the appeal for more information were the New York State Consumer Protection Board and the American College of Allergists.

Fast-food restaurants constitute a $47.1 billion market, making it the fastest-moving segment of the eating place market, according to the National Restaurant Association, which opposes labeling of fast-food ingredients.

"We feel that it is not in the best interest of the consumer -- that it wouldn't give enough information to a person that has an allergy and doesn't know that they do," said Dee Dorothy, spokeswoman for the restaurant group. "Yet, it would create undue anxiety for all restaurant patrons."

But the Center for Science in the Public Interest argues that fast foods are covered with sauces and spices and may contain a number of additives. Jacobson said that consumers rely on ingredient disclosure to avoid substances to which they are allergic or that are linked to diet-related diseases. Certain food dyes, forms of corn sugar and milk solids can lead to allergic reactions in individuals, Jacobson said, while other ingredients -- such as fat, salt, nitrites and saccharin -- have been linked to various diseases.

Unfortunately, he said, "without informative labeling, the composition of fast foods remains a mystery. This leaves health-conscious consumers completely in the dark."

"How many people concerned about heart disease and who fry foods in vegetable oil at home realize that McDonald's and Burger King fry their foods in beef fat and other highly saturated fats?" asked Jacobson.

"Knowing that FDA requires Yellow Dye No. 5 to be listed specifically on all food packages, wouldn't the thousands of people allergic to that chemical be surprised to know that McDonald's uses that dye in sundae strawberry topping, pancake mix and many other products?" Jacobson added.

McDonald's officials could not be reached for comment.

The National Restaurant Association said, however, that if a consumer has an allergy or is concerned about ingredients in a particular fast-food product, he or she should inquire at the place where the food is being sold or ask the restaurant manager.

The Center for Science in the Public Interest said that in its survey of 13 major fast-food chains, only Arby's would provide any significant amount of information about ingredients. The consumer coalition said yesterday that fast-food ingredients could easily be disclosed on labels because most of these products are sold in some form of wrapper or container.

Under the law, most foods that are sold in packages with labels must contain a list of ingredients on that label, but there is no such requirement for food sold at restaurants where menus and recipes change daily and where the food is not sold in wrappers.

The consumer groups also have asked that the chains be required to display posters listing the ingredients of their products so that buyers could look for problem ingredients before ordering.