When Los Angeles County Supervisor Yvonne Brathwaite Burke introduced a motion to study the effects of a trans fat ban, health critics cheered and restaurant owners sneered.

And some restaurants have decided to give it up on their own.

CKE Restaurants Inc., which owns Carl’s Jr., Hardee’s, La Salsa, and Fresh Mexican Grill restaurants said it would begin testing trans fat-free cooking at its Carl’s Jr. and Hardee’s restaurants soon.

Universal Studios effectively eliminated trans fats from its menu last month, after the Walt Disney Co. said it would slowly phase out trans fats at all of its parks.

It’s a philosophical debate for some chefs, however. Many chefs, even those who have eschewed low-grade, fatty ingredients, balk at being told how to cook.

“One of the things that does scare me about this is the precedent that the government is going to determine what we can or can’t eat, even if it’s for the sake of everyone involved,” said Kris Morningstar, chef at Blue Velvet in downtown L.A. He doesn’t use trans fats in his cooking, but is strongly opposed to the possible ban of foie gras, the fatty livers of ducks who have been force fed.

The California Restaurant Association shares Morningstar’s take.

“We have a fundamental concern about the government banning what amounts to household items, approved by the FDA,” said Jot Condie, president of the association. “Consumers are smart enough to know that items that are fried or baked goods are not health foods and ought to be consumed in moderation.”

Trans fats are created by the hydrogenation of oils. The process was created in the 1950s to extend the shelf live of foods. Trans fats are particularly prevalent in baked goods, salad dressings and deep-fried foods.

Trans fat bans or partial bans have already been approved in New York and Chicago. The proposal to the L.A. County Board calls for a study by the Public Health Department.

Los Angeles-based California Pizza Kitchen Inc. said it has already eliminated trans fats from its menu and wouldn’t be affected the ban.

The chain began reducing its trans fat content in 2003.

IHOP Corp. and La Brea Holdings Inc. declined to comment for this story.

The study, which will include input from community health organizations, restaurants and fast food purveyors and a nutrition task force, will be presented to the board on Jan. 30 and a vote will be taken later.