But in the 14 states that have so far proposed a ban or restriction, not a single bill has been passed as the year draws to a close. This month, Ohio became the 15th state to make such a proposal.
New bills often take time to wind their way through committees and come up for a vote. But the legislation has also faced strong opposition from the National Restaurant Association and its state-level affiliates — although the Massachusetts' group recently said it wouldn't fight that state's bill.
The national association says it doesn't oppose phasing out trans fats but objects to what it calls "inflexible bans with unrealistic timetables."
"It's not as easy as just dumping in a new oil," said Sheila Weiss, director of nutrition policy for the group.
A voluntary, gradual approach would "significantly diminish the impact and unintended consequences of an outright ban," Richard Mason, lobbyist for the Ohio Restaurant Association, wrote in a letter to Ohio's trans fat bill sponsor.
The industry points to the voluntary no-trans-fat movements at fast-food restaurants such as Wendy's, KFC and Taco Bell to emphasize to lawmakers that there's no need to get government involved. A ban could force restaurants to switch to saturated fats — which also contribute to heart disease — if they haven't had time to find a healthier alternative, the industry says.
But proponents of the bills said it's relatively easy to switch to other oils such as canola or corn oil, pointing to New York City, where restaurants have complied with the ban's first phase — which applies to oils, shortening and margarine used for frying and spreading — without much fanfare.
Sylvia's, a soul food restaurant in Manhattan, said it switched to frying without trans fat oil before the city's ban went into effect in July. The transition was easy except for a few desserts, said restaurant marketing director Trenness Woods-Black.
"We switched and no one noticed the difference. We still have super crispy fried chicken," she said.
But some bakeries around the country have said it's hard to make baked goods with the same quality without trans fats. The main source of trans fat is partially hydrogenated oils, created when hydrogen is added to liquid cooking oils to harden them for baking or for a longer shelf life.
The Philadelphia City Council approved a bill to exempt bakeries from that city's ban after many bakeries complained.
Critics say the restaurant group's argument is undercut by the success restaurants have had getting rid of trans fats.
"The restaurant association has a very strong lobbying effort and they've made a major effort to keep this from getting passed," said Julie Greenstein, deputy director for health promotion policy at the Center for Science in the Public Interest in Washington. In many cases, the center has been the driving force behind trans fat bills.
A New York Democratic legislator, Felix Ortiz, has been trying since 2004 to get a trans fat restriction into state law. But the restaurant industry has cultivated members on key committees, Ortiz said. His latest bill focuses on chain restaurants.
"We are going to get it done," said Ortiz, who pushed through New York's ban on talking on a cell phone while driving.
The other states that have proposed a ban or restriction on trans fats in restaurants are Maryland, Michigan, Illinois, New Jersey, New Hampshire, Rhode Island, South Carolina, Tennessee, Vermont and Hawaii.