There's a new label in town: Trans fat-free labels are on everything from snack foods to cereals. And by 2006, all food manufacturers will be required to divulge just how much of the substance is in their products.

According to the Food and Drug Administration (FDA), trans fats, or partially hydrogenated fats, are in nearly half of all cereals, 70 percent of cake mixes, 70 percent of chips and crackers, 80 percent of frozen breakfast baked goods and 90 percent of all cookies.

There's probably no more important food issue right now than trans fats, says Richard Delaney, MD, a cardiologist and preventive medical specialist in Milton, Massachusetts, "which is why paying attention and reading labels is so important."

Some manufacturers are ahead of the deadline and have removed hydrogenated fats entirely from their products. Some will wait until the bitter end before listing trans fat content. And others will use an existing loophole and tell you that their products are trans fat-free, even though that may not be entirely true.

Looking at the Label
This gaping loophole is due to an FDA leniency that allows manufacturers to say that a product has no trans fats if it contains fewer than 0.5 grams of hydrogenated fats per serving. So if you eat more than the single serving size or eat a couple of trans-free products at the same time, the 0.5 gram rule means nothing.

The ruling came about because the FDA considers 0.5 grams to be a negligible health risk, even though the Institute of Medicine says that any level of trans fats is dangerous to health.

But despite this loophole in the regulations, you can still determine the amount of trans fats in your food, regardless of whether or not it's listed on the label. As a general rule, if the trans fat content is missing from the nutrient panel, add up the number of grams of each type of fat (saturated, polyunsaturated and monounsaturated) and subtract this amount from the total fat; the difference is most likely trans fat (The Trans Fat Solution, Kim Severson, Ten Speed Press, 2004).

Fooling Mother Nature
So just what are trans fats, besides another one of man's stupid attempts to fool Mother Nature? Partially hydrogenated fats are made by bombarding unsaturated liquid vegetable oils -- such as soybean oil, canola, cottonseed and corn oil -- with hydrogen gas and a metal catalyst (nickel or platinum). Food manufacturers like these fats because they make food crispy and flaky, and best of all, trans fats have a terribly long shelf life.

There are also natural trans fats, produced in small quantities in the intestines of ruminant animals such as cows. As a result, we get small amounts of naturally occurring trans fats from butter, dairy and meat. We all know the party line about eating too many animal fats. However, these fats also contain helpful fatty acids, such as lauric acid (acts as an antiviral), stearic acid (lowers cholesterol) and conjugated linoleic acids -- all believed to play a role in immune function, metabolism and cell communication when eaten in reasonable quantities.

The problem with hydrogenated fats is that the human body isn't quite sure what to do with them. It all comes down to the shape and chemical bonds in fat molecules. Liquid fat molecules have fewer hydrogen bonds than saturated fats, allowing them to bend or kink. These kinks help keep cells pliable and permeable, which is essential for good health. Saturated fats from butter or even lard pack together tightly, forming a straight molecule that the body recognizes and metabolizes when eaten sparingly.

When manufacturers turn a liquid fat into a hydrogenated fat, the molecules straighten out to form something that looks a little like a saturated fat and a little like an unsaturated fat. "Under a microscope, they look like plastic molecules," says Neil Bloomquist, president of Spectrum Naturals, Inc. of Petaluma, California. The body tries to use the hydrogenated fat in the same manner as a liquid fat. And when that's unsuccessful, the body stores the fat, and it begins to build up, eventually leading to a host of diseases including type 2 diabetes, arthritis and cardiovascular disease.

Good Fat/Bad Fat
Unfortunately, since the 1980s, we've been led to believe that saturated fats are the vilest fats imaginable, which isn't entirely true. In the late 1980s, the American Soybean Association, citizens' health groups and physicians campaigned against saturated fats including lard, butter and tropical oils, citing hydrogenated oils as a healthier alternative. Americans ignored their grandmothers' pleas to make pie crusts from lard; margarine replaced butter; and tropical fats were essentially banished to offshore populations.

That change turned out to be deadly. In 1994, the Harvard School of Public Health estimated that at least 30,000 people die each year of coronary heart disease as a result of eating hydrogenated fats, and that for each 2 percent increase in calories from trans fats, a woman's coronary risk escalates by 93 percent.

While no one is saying eat all the butter and lard you want, saturated fats can have a place in our diets -- if we eat enough unsaturated fats, particularly ones high in omega-3 fatty acids. The bad science that pushed tropical fats out of American diets is being overshadowed by new research showing that, although they are saturated, palm fruit oil and coconut oils certainly aren't as bad as hydrogenated vegetable oils. In fact, coconut oils contain lauric acid, known for its antibacterial and antiviral properties, and palm fruit oils are an acceptable alternative to trans fats for many commercial products. Some stores now carry palm fruit oil shortenings, shortening blends and coconut oils -- each a fine alternative to hydrogenated fats.

"It's important to get rid of some of the myths about saturated fats," Bloomquist says. "The new science is countering old ways of thinking."

Delaney says that when you rid your diet of trans fats, marked changes occur within a relatively short time period. From experience, Delaney has seen blood triglyceride levels improve, insulin resistance disappear and risk of stroke and heart attacks decline when patients replace trans fats with healthful fats from flax, fish oil and nuts. Delaney also advises women to stay away from trans fats to avoid developing preeclampsia in pregnancy and to lower their risk of developing breast cancer.