As the negative effects of trans fatty acids have become more apparent in the past years, many companies, restaurants, and now even cities, are seeking to eliminate them as much as possible from their products.

The New York City Health Department unveiled a proposal last week that would require restaurants to eliminate all trans fats from their menus. Chicago has also proposed a similar ban but the measure would only apply to companies with annual revenues of more than $20 million, specifically targeting fast-food chains.

Trans fatty acids, more commonly called trans fats, are most often found in processed foods that contain partially hydrogenated oils. Trans fats are unhealthy because they raise the body’s bad cholesterol and lower the good cholesterol. Canola, olive, and vegetable oil are among the ones that do not contain trans fats.

Harvard University Dining Services (HUDS) has been very active in its efforts to eliminate trans fats from dining hall food. All products made from scratch by HUDS no longer have trans fats after the company switched from partially hydrogenated oil in 2003. Dining hall margarine, peanut butter, muffins, cookies, and even chicken fingers and french fries all no longer contain trans fats. Of the desserts, only German chocolate brownies, Oreo cake, congo bars, and chocolate truffle do not qualify.

Crista Martin, director of marketing and communications for HUDS, said that the University constantly uses the question of trans fat as criteria when deciding which products to purchase. “It is top of mind in the industry right now,” Martin said.

Cambridge Public Health Department’s interim chief of public health, Karen A. Hacker, revealed that the department is currently examining the issue and New York City’s approach to it. In the mean time the department is “doing tremendous things for obesity prevention in Cambridge,” she said.

Hacker is directing several programs as alternatives to a ban on trans fats that combat obesity and other health issues. “Golden Shoes” is a program where children search for golden-colored shoes throughout Cambridge to encourage exercise. In the Cambridge Public Schools, health progress reports are distributed to parents to get them involved in monitoring their children’s health.

On a smaller scale, many restaurants in Harvard Square are taking the initiative to eliminate trans fats from their menus. Very few use partially hydrogenated oil, even for foods generally seen as less healthy, such as pizza or burgers. Legal Seafood and Pizzeria Uno are among the restaurants leading the elimination of trans fats in the United States, according to their websites. Au Bon Pain is now also offering many trans fat-free options.

Richie Bezjian, co-owner of Leo’s Place in the Square, applauded New York City’s efforts to ban trans fats. “Trans fats are so unnecessary,” Bezjian said. “Restaurants should be first to implement such measures.” He said he does not serve trans fats.

Although most restaurateurs support efforts to fight against the risks associated with trans fats, some do not appreciate an approach through government. Adam J. Penn, the owner of Veggie Planet, said he has mixed feelings, although he primarily uses organic and olive oils. “I definitely think it is good to be as health conscious as possible, but my first reaction is that it does seem a little Big Brother-ish.”

Bill Bartley of Mr. Bartley’s Burger Cottage, agreed: “I think people are intelligent, and they can make their own choices.” But he said he only fries food in canola oil.

School of Public Health Stare Professor of Epidemiology and Nutrition Walter C. Willett wrote in an e-mail that the adverse metabolic effects of trans fats translate into tens of thousands of premature deaths from heart disease in the United States each year. He also said that trans fats are likely the cause of 40 percent of Type 2 Diabetes in the country. In Europe, most food companies have eliminated trans fats from their products, and Denmark has completely banned the sale of products containing trans fats, according to Willett.

“These bans are important because they can put pressure on the food industry and [Food and Drug Administration] to do what should have already been done by now,” Willett said.