NEW YORK – After two years of secret taste tests, KFC said Monday it would stop frying chicken in artery-clogging trans fats, but New York City restaurants being urged to do the same say it’s not so easy.

KFC’s announcement, which won praise from consumer advocates, came an hour ahead of a public hearing on a proposal that would make New York the first U.S. city to ban the unhealthy artificial fats.

Industry leaders dished up a plateful of reasons why such a plan shouldn’t be adopted in the nation’s restaurant capital.

The move would be a “recipe for disaster that could be devastating to New York City’s restaurant industry,” said E. Charles Hunt, executive vice president of the New York State Restaurant Association.

The shift by KFC and a handful of other fast food chains – and the effort by New York health officials – mark an aggressive crackdown on an ingredient that is consumed in large doses around the country.

An average American eats 4.7 pounds of trans fats a year, and the oil is used as a shortening in baked goods like cookies, crackers and doughnuts, as well as in deep frying. Experts say a ban in New York would reverberate across the country because the city’s food industry is so large.

The ban initially would have been a harsh one for KFC. But the company now says that by next April, all 5,500 of its U.S. restaurants will have switched from trans fat-rich partially hydrogenated vegetable oil to a new soybean oil believed to be less likely to cause heart disease.

Some KFC sites have already made the switch in secret trials to see if customers would notice They did not, and KFC President Gregg Dedrick said he was confident the switch won’t prompt complaints about taste.

“There is no compromise,” he said at a Manhattan news conference. “Nothing is more important to us than the quality of our food and preserving the terrific taste of our product.”

Health advocates applauded the company’s switch. The Center for Science in the Public Interest, which sued KFC last spring over the trans fat content of its food, announced Monday that it was withdrawing from the lawsuit.

“Colonel Sanders deserves a bucket full of praise,” said CSPI executive director Michael Jacobson. “If KFC, which deep-fries almost everything, can get the artificial trans fat out of its frying oil, anyone can.”

Burger King also said Monday that it hopes to begin testing trans fat-free cooking in some restaurants within 90 days. Wendy’s has already switched to a zero-trans fat oil. McDonald’s had announced that it intended to do so as well in 2003, but has yet to follow through.

The New York hearing on the proposed trans fat ban was packed with doctors and paid industry spokesmen. Long lines at the building’s security checkpoint and an overflowing hearing room might have deterred ordinary citizens or restaurant owners from speaking.

But industry representatives like Hunt spoke out.

“This ban threatens popular dishes and affordable menus,” he said. “The city needs to get serious about working with, not against, our restaurant owners.”

He and others said a ban would leave cooks unable to find proper replacement ingredients, and force some to switch to bad alternatives.

Sheila Cohn Weiss, director of nutrition policy for the National Restaurant Association, suggested that restaurant owners in need of a quick fix would simply switch to another unhealthy substance like palm oil, which contains unhealthy amounts of saturated fat.

“This is a switch that cannot happen immediately,” she said.

KFC has concerns about supply, too.

Dedrick said KFC and the creator of the new oil, the Monsanto Corp., had to work with seed oil processors to persuade farmers to grow more of the special soybeans used in the product. Among other things, farmers were offered a price premium to grow the new soybeans.

Monsanto spokesman Chris Horner said he expected the farmland devoted to the company’s new seed to triple next year to 1.5 million acres, up from 500,000 acres this year and 100,000 in 2005.

Still, he added, demand for trans-fat-free oils has the potential to outpace supply.

New York’s health commissioner, Dr. Thomas Frieden, said officials have heard the supply argument before and rejected it as unsupported.

“We’re confident that there is ample supply of healthy trans fat alternatives,” Frieden said, although he added that officials might consider giving restaurants more time. The New York City Board of Health is expected to vote for the ban in December with an 18-month period for a full phase-in.

Louis Nunez, president of New York’s Latino Restaurant Association, said a quick survey by his group shows at least 980 of its members don’t know what trans fats are.

“If this goes in with no education, there is going to be an avalanche of fines,” Nunez said.

Even with the development of new oils, finding replacements for every recipe may be tough.

KFC said that even after its changeover, some menu items will continue to contain artificial trans fats, including its popular biscuits.

Although not fried, the biscuits contain a trans fat shortening that has proven difficult to replace. Dedrick said the company would continue trying to develop a substitute.