Junk food lovers have another risk to consider when eating chips, cookies and fast food: trans-fatty acids, or trans-fats.

Trans-fats are manmade fats that form when vegetable oils are converted to solids for use in food products, a process called hydrogenation.

Epidemiology professor Lisa Harnack said it is trans-fat content that gives margarine sticks the ability to keep their solid form. She said trans-fat can be found in a wide variety of foods.

Harnack recently completed a study at the University that found that overall trans-fat intake in the Twin Cities metropolitan area declined from 1980 to 1997.

Harnack said the study is helpful because it showcases a decline resulting from many factors, and a step in the right dietary direction for Twin Cities residents.

People are generally eating less fats, she said.

“A lot of foods have partially hydrogenated fats and oils,” she said. “If it says it has a partially hydrogenated oil in it, it most likely has trans-fatty acid.”

Trans-fats are an unhealthy form of cholesterol, Harnack said. While some types of fat are good for the human body, Harnack said trans-fats serve no dietary purpose.

“Biologically, there is nothing good about them and no reason to have them in our diet,” she said.

While many people understand the health risks associated with a high-cholesterol diet, she said, trans-fat has remained largely below the public-awareness radar.

Research indicates that trans-fatty acids raise the level of bad cholesterol and the risk of coronary heart disease, according to the U.S. Food and Drug Administration.

But a reduction in trans-fat consumption is also a result of changes within the food industry itself, she said.

“Manufacturers are reducing the amount of trans-fat in their products,” she said.

Some trans-fat reductions are the result of moves within the food industry that were not due to health concerns, she said. For example, the makeup of common cooking oils has changed over the years, she said.

Earlier this year, the FDA ruled that all nutrition labels on food products must contain trans-fat content by 2006, according to the FDA Web site.

Harnack said requiring such food manufacturers to put trans- fat content on their labels did not happen overnight.

“It has been push and shove with this,” she said. “Eventually, it won out.”

Holding a package of Oreos in one hand, global studies junior Jeff Hawley said he has only recently heard about the perils of trans-fat, and that it is now a concern for him, but within reason.

“I’m not hugely into eating healthy,” he said. “But it’s good to know about because the food companies shouldn’t put things in that people don’t know about.”