Trans-Fat-Free Food: What's the Truth?

The skinny on labels, calories, and what trans fat means to your diet.

By Kathleen Zelman, MPH, RD/LD
WebMD Weight Loss Clinic - Feature

Reviewed By Louise Chang, MD

We've made great progress since January 2006, when Congress required that trans fat content be listed on food labels. Food manufacturers and restaurants that used the unhealthy fats have scrambled to find alternatives so they can boast of their "trans-fat-free" foods. Bills to limit or ban trans fats in restaurants or school cafeterias have been introduced in at least 20 states.

Artery-clogging trans fats have been made out to be the bad guy in American diets -- and there's good reason for that. But the truth is that just because something is trans-fat-free, that doesn't necessarily mean it's healthy. Experts agree that using healthy fats, such as canola and olive oil, is better than using the artery-clogging trans or saturated fats. Yet all fats are loaded with calories -- and so need to be limited in our diet.

To make it even more confusing, labels boasting "zero trans fat" don't always mean a food is completely trans-fat-free. By law, such foods can contain small amounts of trans fats per serving. You'll still need to turn over the package and look at the list of ingredients and the nutrition facts panel.

So just what are trans fats? There are two types -- the naturally occurring type, found in small amounts in dairy and meat, and the artificial kind that results when liquid oils are hardened into "partially hydrogenated" fats. Natural trans fats are not the ones of concern, especially if you usually choose low-fat dairy and lean meats. The real worry in the American diet is the artificial trans fats, which are used extensively in fried foods, baked goods, cookies, icings, crackers, packaged snack foods, microwave popcorn, and some margarines.