California has become the first state to ban trans fats in restaurants. Under the new law, trans fats, long linked to health problems, must be excised from restaurant products beginning in 2010, and from all retail baked goods by 2011. Packaged foods will be exempt.

New York City adopted a similar ban in 2006, and several cities throughout the U.S. have done so as well.

But having the requirement imposed on the most populous state’s 88,000 restaurants is a major gain for the movement against trans fats. That movement has been led by scientists, doctors and consumer advocates who trace the largely synthetic fat to a variety of ailments, principally heart disease.