Trans is created when oils are "partially hydrogenated." Hydrogenation is what turns liquid oil into Crisco or stick margarines. It makes pie crusts flakier and french fries crispier.

Now that you know what trans fat is lets talk about French Fries. According to an article in Nutrition Action Healthletter, Fries cooked in partially hydrogenated vegetable shortening, such as McDonald's, Arby's, and Hardee's have roughly as much artery-clogging fat as if they were fried in lard. Burger King and Wendy's fries are even worse.

The bad thing is that if you looked at a brochure, you'll see only the amount of saturated fat the fries contain. Nothing about trans. That means that half the artery-clogging fat is invisible.

Avoiding Trans-fat

1. Look for foods that contain no "vegetable shortening" or "partially hydrogenated" oil.
2. Avoid deep-fried foods. Buy lower-fat margarines, chips, crackers, cookies.
3. Use olive or conola oil instead of butter, margarine, or shortening whenever possible.
4. If you use margarine, buy tubs rather than sticks. Buy "light, "low-fat," or "fat-free".
5. Foods that are "cholesterol free," "low-cholesterol," "low-saturated-fat," or "made with vegetable oil" may not be low in trans fat.