Scoma's restaurant in San Francisco did away with trans fats nearly five years ago.
"At the time there weren't really that many products out there. Everything was about stabilized oils," said Kelly Bennett of Scoma's restaurant.
Nora Norback is a dietician at Kaiser.
"Inexpensive, don't go bad easily, they can heat to very high temperatures -- so that makes it a good thing for cooking, unfortunately it doesn't make it such a good thing for our health," said Norback.
Studies have shown that trans fats increase the bad cholesterol, while lowering good cholesterol. But today, restaurants have more choices. Even distributors who once sold trans fats to restaurants have moved on to other healthier choices.
"I sort of draw the correlation with cigarettes, nobody really knew and people defended the fact that cigarettes weren't bad for you," said Bennett.
Trans fats got a lot of negative publicity in 2003, when Stephen Joseph sued Kraft, the makers of Oreo cookies.
"After two days, Kraft said there is nothing wrong with our cookies, and after four days Kraft caved because of all the publicity and said 'ok, we'll remove the trans fat from everything,'" said Joseph.
To his surprise, Joseph received a lot of hate emails and even death threats.
"Communist, pinko, Nazi, terrorist," said Joseph.
Still, other food companies followed Kraft's actions and so did other cities. Tiburon was the first to ban trans fats in restaurants in 2004 and New York City in 2006. And today California is the first state to do so.
Bakeries still have another year to comply with the law. The industry argued it needed more time to come up with adequate substitutions. Violators will face fines from $25 dollars up to $1,000.