Trans fat has become a hot topic. Fast-food chains such as Arby's, Wendy's and Taco Bell have stopped using it to make some of their menu items, and New York City approved a ban on the substance.

While the term -- short for trans-fatty acids -- is no longer just jargon used by dieticians, most people don’t really know what it is, or how it is linked to heart disease.

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Trans fat is the result of a chemical process called hydrogenation, in which hydrogen is added to liquid vegetable oils to make them more solid, according to the American Heart Association. It is used by food processors to give products more shelf life, add texture and better taste, the association's Web site says.

But it comes with a danger.

“The main reason they are bad is they raise your bad (low-density lipoproteins) cholesterol and at the same time they lower your good (high-density lipoproteins) cholesterol. It has a double-whammy effect," American Dietetic Association spokeswoman Marisa Moore said.

Research shows too much bad (LDL) cholesterol causes clogged arteries and can increase the risk of heart disease and stroke, according to the AHA.

The main sources of trans fat are shortening and stick margarine. Snack foods, doughnuts, cookies, cakes and anything with hydrogenated or partially hydrogenated oils have trans fats.

With all those tasty sources, the U.S. Food and Drug Association said the average American adult gets about 2.6 percent of her daily calories from trans fat.

Moore said that healthier alternatives such as trans-fat-free shortening and tub margarine can cut your consumption.

"I recommend you use heart-healthy fat like canola oil. You won't notice a difference in taste," Moore said.

Reducing Percentages

Changing cooking oils could help people make trans fat a smaller part of their diets.

In June, the AHA released recommendations that people limit themselves to about 2 grams of trans fat per day in an average diet about 2,000 calories per day. That’s 1 percent of their calories.

"Trans fat content will vary with food products, so this may be the equivalent of one to two cookies or half of a medium (order of) fries. Consumers are encouraged to read food labels and visit restaurant Web sites for the most up-to-date nutrition information," according to Moore.

"I think it’s important for people to understand how much their trans fat intake should be," she said.

Moore said part of the focus on trans fats is a result of its appearance on food labels, and that 2006 has seen success in bringing attention to trans fats. Since January 2006, manufacturers are required by the FDA to list trans fat content on nutrition labels that appear on food packaging.

“As a dietician, we’re trying to get the word out in educating the public," she said.

Diane Oahodny, owner of Campbell's Nutrition in Des Moines, said she thinks the attention on trans fats is a good thing, but is concerned when there's an all-out ban on food substances.

Oahodny said hopefully people will discontinue using them on a voluntary basis, such as KFC did in its restaurants.

Other business people agree that awareness is a better route to take than legal bans on trans fat.

"As a small business owner of a coffee shop, I'm a little hesitant to side with regulation of behavior, although I believe that in this case, anything we can do to encourage the fast food restaurant industry to clean up its act the better," said Phil James, owner of Mars Cafe in Des Moines.

Other Fats Still Troublesome

The AHA also says that total trans fat and saturated fat combined should be less than 10 percent of people's daily calorie intake.

Saturated fats are found in animal products such as beef, lamb, butter, cream, pork, milk, and some plants that have coconut oil, palm oil and palm kernels.

Americans typically consume four to five times as many saturated fats as they do trans fats, according to the AHA. Moore said there’s an effort to move consumers to choose items that contain good fats, which are monounsaturated and polyunsaturated. They are considered good because they help lower bad cholesterol, but they do not help raise good cholesterol.

She said these good fats can be found in olive oil, peanut oil and canola oil and can be substituted for trans fats.

Exercise Still Important

“The best way to increase good cholesterol is through aerobic activity," Moore said.

General guidelines call for 30 minutes of exercise daily, but she said that if people can work toward 60 minutes a day, that would be even better.

The AHA recommends a diet that balances caloric intake with the amount burned, with vegetables, fruit, whole-grain foods, fat-free and low-fat dairy products, lean meats, poultry, fish and foods with healthy fats making up most of what you consume. Other Links:

Trans Fat And Your Wallet

Good Fats V. Bad Fats

Making Your Kids Fat?