by Bryan Darrow | January 01, 2007

What are trans fats, and why are they the new bad boys on the food pyramid? “Trans fat is formed when liquid oils are made into solid fats through a process called hydrogenation, which increases a food’s shelf life,” according to Marisa Moore, RD, American Dietetic Association spokesperson. This process creates fats that raise levels of LDL cholesterol (sometimes known as “bad” cholesterol), which in turn increases the risk of heart disease.

Products with fats that are made through a chemical process, like shortening and stick margarine, are common offenders. Doughnuts, baked goods and other snack foods often have trans fats, as well. As a rule, avoid anything with “hydrogenated” or “partially hydrogenated” in the ingredient list. And read nutrition information labels: The percentage of trans fats must be listed.

For more healthful options, buy soft margarines that are trans-fat free, and chose natural, heart-healthy oils like olive or canola oil. And when coating a pan for cooking or baking, it’s best to use a nonstick spray.