Where Are Trans Fats Hiding?

How do you limit these harmful fats? Print out this list of 10 foods to beware and take it to the supermarket!

By Jeanie Lerche Davis
WebMD Weight Loss Clinic - Feature

Reviewed By Charlotte Grayson, MD

Trans fatty acids -- better known as "trans fats" -- have emerged as the food industry's newest bad boy.

Trans fats are formed during a process called hydrogenation, which converts a relatively healthy, unsaturated liquid fat -- like corn oil or soybean oil -- into a solid one. This gives the fat longer shelf life, so it's convenient for restaurants and food manufacturers.

The problem: The body treats hydrogenated fat more like saturated fat, like butter or animal fat. Saturated fat has long been known to clog arteries -- and some studies indicate trans fat may be a bit more evil. But on food labels, trans fatty acids are not included under "saturated fat."

What to Do, What to Do...

To help consumers, the Food and Drug Administration is requiring that all food labels list trans fats by January 1, 2006. Until then, how can you know which foods are safe and which contain these stealth fats?

For guidance, WebMD turned to the nation's nutrition gurus -- the experts at the American Dietetic Association (ADA).

"Until now, consumers were really in the dark about trans fatty acids. In fact, most people are probably very confused right now," says Cindy Moore, MS, RD, an ADA spokesperson. Moore is also director of nutrition therapy at the Cleveland Clinic Foundation.

Here are four ways you can make healthier choices at the supermarket. Immediately below these suggestions, we list the top 10 types of food loaded with trans fats. Print out this list to become a wise, safer shopper.

#1. Limit or avoid both saturated and trans fats types of fat.

There's no magic number to shoot for here, no "X" grams of trans fatty acids allowed in your daily diet, Moore tells WebMD. Just realize that the more fast food and packaged food you eat, the more trans fats you are getting in your diet.

#2. Use nutrition labels to estimate the trans fat content in a product.

Add up the saturated, monounsaturated and polyunsaturated fat. If they are less than the "total fat" number, the remainder is likely trans fat, says Moore.

#3. Remember: Reduced-fat and fat-free foods will have virtually no trans fat in them.

#4. Look for the term "partially hydrogenated oil" on the package ingredients list.

If partially hydrogenated oil is first on the list -- the product may contain trans fat.

Some manufacturers have already changed their recipes and formulas to reduce trans fats to less than 0.5% of fats. The ingredient list may state "partially hydrogenated oil," but if the packaging says "Contains No Trans Fats," you can believe it, says Moore.

There's more good news. "It's very likely that in the next few months, we'll be seeing more and more products without trans fats" as the food industry adjusts to the new consumer awareness, Moore tells WebMD.


"Margarine is a twisted sister -- it's loaded with trans fats and saturated fats, both of which can lead to heart disease."

The Top 10 "Trans Fat" Foods:

1. Spreads. Margarine is a twisted sister -- it's loaded with trans fats and saturated fats, both of which can lead to heart disease. Other non-butter spreads and shortening also contain large amounts of trans fat and saturated fat:

  • Stick margarine has 2.8 grams of trans fat per tablespoon, and 2.1 grams of saturated fat.
  • Tub margarine has 0.6 grams of trans fat per tablespoon, and 1.2 grams of saturated fat.
  • Shortening has 4.2 grams of trans fat per tablespoon, and 3.4 grams of saturated fat.
  • Butter has 0.3 grams of trans fat per tablespoon, and 7.2 grams of saturated fat.

Tip: Look for soft-tub margarine, because it is less likely to have trans fat. Some margarines already say that on the packaging.

[Important note: When you cook with margarine or shortening, you will not increase the amount of trans fat in food, says Moore. Cooking is not the same as the hydrogenation process. "Margarine and shortening are already bad, but you won't make them any worse."]

2. Packaged foods. Cake mixes, Bisquick, and other mixes all have several grams of trans fat per serving.

Tip: Add flour and baking powder to your grocery list; do-it-yourself baking is about your only option right now, says Moore. Or watch for reduced-fat mixes.

3. Soups. Ramen noodles and soup cups contain very high levels of trans fat.

Tip: Get out the crock-pot and recipe book. Or try the fat-free and reduced-fat canned soups.