What Are Trans Fats?
Trans fats, which are considered to be some of the most dangerous forms of fat, are engineered from liquid oils through a process known as hydrogenation.
Trans fats were once thought to be the ultimate fat because they enhance the way foods taste. They also extend the shelf life of foods and make crisp foods crunchier and creamy foods creamier. And the price is lower than other fats.
As a result, trans fats found their way into many of Americans' favorite processed foods. Only later did doctors begin to realize how damaging they can be to the heart.
Come Out, Come Out, Wherever You Are
Unhealthy trans fats lurk in most processed foods, including cookies, baked goods, popcorn, margarines, shortenings, crackers, doughnuts, chips, frozen waffles, and french fries.
Eighty percent of trans fats come from processed foods; the other 20% occur naturally in meat and dairy products. Although meat and dairy contain small amounts of trans fats, they can also be loaded with the equally unhealthy saturated fats, says nutritionist Elizabeth Ward, MS, RD.
Trans fats in meat and dairy are only a concern to people who eat large quantities of full-fat dairy and high-fat meat, says Ward. Choosing low-fat dairy and lean meats will reduce the harmful trans and saturated fats.
Ward advises that we shift from fat-laden processed foods to more natural, wholesome foods that are chock full of disease-fighting, healthful nutrients.
"Eat a diet of fresh, whole ingredients, limit the amount of processed foods in your diet, and always choose the lowest-fat variety of meat and dairy to wipe out the bulk of harmful trans fats."
How Much Is Too Much?
"There is no dietary recommendation for trans fatty acids; consumption should be kept as low as possible" Theresa Nicklas, DrPh, tells WebMD. Nicklas is a member of the 2005 Dietary Guidelines Advisory Committee.
Trans fats increase LDL "bad" cholesterol levels, which increases the risk for heart disease, says Nicklas, who is also a professor of pediatrics at the Baylor College of Medicine.
"The Dietary Guidelines Advisory Committee recommendation is to limit the intake of trans fats, and with the help of food manufacturers, we can help educate Americans to make better food choices" says Nicklas.
Nutrition researcher Alice Lichtenstein, DrSc, says in addition to watching trans fats, one of the best ways to lower your risk of heart disease is to reduce the amount of animal fats in your diet as much as possible.
Total fats should make up no more than 25%-35% of your total daily calories, Lichtenstein tells WebMD. For example, someone who eats 2,000 calories a day should get 500 to 700 calories from fat -- about 55 to 75 grams of fat a day. And most of this should come from healthy fats.
Healthier oils include vegetable oils, such as corn, soybean, canola, and olive oils -- but not the tropical palm or coconut oils. Other ways to skim the saturated fat in your diet is to choose lean meats, such as skinless chicken and turkey, lean beef, and low-fat dairy, Lichtenstein says.
Changing Face of Foods
Food manufacturers are now looking for suitable replacements for trans fats.
The challenge to the food makers is to preserve the same great flavors while eliminating or minimizing the unhealthy trans fats. A flurry of "trans-fat free" products have popped up in recent years.
Trans-Fat Free Doesn't Equal Healthy
But just because a food package boasts "zero grams of trans fats" does not mean it is necessarily a healthy food says Ward, author of the 2006 Idiot's Guide to the New Food Pyramids.
"Products with 0.5 grams of trans fat per serving can be labeled as '0' and if you eat large portions, the trans fats can add up quickly. Always check the total fat, saturated fat, and calories because it may be lacking in trans fats but it could be loaded with saturated fats or calories" she warns.
Remember trans fats when eating out. Keep in mind when you smell the aroma of the freshly baked doughnuts or french fries that these foods may not be labeled on the menu but they are a huge source of trans fats in our diets.
Mandatory labeling of trans fats should help improve the health of our nation, says Lichtenstein. Consumers will now have more choices and hopefully a better understanding that a food with the least amount of saturated and trans fats is a healthier option.
Sources: Theresa Nicklas, DrPh, professor of pediatrics, Baylor College of Medicine; 2005 Dietary Guidelines Advisory Committee member. Alice Lichtenstein, DrSc, professor of nutrition science and public policy, Friedman School, Tufts University, Boston. Elizabeth Ward, MS, RD, author, The Pocket Idiot's Guide to The New Food Pyramids, 2006.
By Kathleen Zelman, MPH, RD
Reviewed by Michael W. Smith, MD
© 2006, WebMD Inc. All rights reserved