Millions of Americans rely on food labels to gauge how much fat they are eating, but scientists and even some food industry experts say the labels lack one very important listing: trans fat.
These little-known phantom fats are present in everyday foods made with vegetable shortening, Good Morning America's consumer correspondent Greg Hunter reported.
Trans fats, also called trans fatty acids, are the product of a process called partial hydrogenation that converts liquid vegetable oils into solid fats. Used to make margarine, shortening, baked goods and fast foods, the trans fats increase a food's shelf life and enhance its flavor.
But that flavor boost can take a toll on health. Studies cited by the Center for Science in the Public Interest (CSPI) suggest trans fat may raise cholesterol levels and lead to clogged arteries. Despite the findings, trans fat is not listed on any ingredient label.
Left Off Labels
"There are two kinds of heart-damaging fats: saturated fats, which are clearly listed on food labels, and trans fat," said Margo Wootan, a scientist at the CSPI. "Trans fat is not included with the other heart-damaging fats on food labels."
The amount of trans fat can be determined with a little math, but only if a food's nutritional label lists the grams of total, saturated and unsaturated fat. Add the saturated and unsaturated grams of fat, and subtract from the total fat, and the difference, if there is one, is trans fat. But the flaw with that formula is that manufacturers do not have to list the unsaturated fat.
And because trans fat is chemically different from saturated fat, it is not lumped in with the listing for saturated fat, which also raises the risk of heart disease.
Small amounts of trans fat occur naturally in certain foods, but most trans fat is added from hydrogenated vegetable oil, found in thousands of packaged foods and used by thousands of restaurants to fry chicken, fish, potatoes, doughnuts and other foods.
The CSPI is trying to convince the Food and Drug Administration to include trans fats on food labels. Items could have twice as much fat in them as is listed on food labels on the package, Wootan said.
The CSPI tested 40 products for trans fat and found that Americans may be eating much more total fat then they realize. Parkay margarine lists on its label that it has two grams of saturated fat, but lab tests show that it actually has another three grams of trans fat, Wootan said.
FDA May Change Labels
A few products now say trans fat free. To spot a food with trans fat, look for ingredients like hydrogenated oils, margarine or shortening. It can be confusing, because food labels on items such as Original Triscuits may boast of having no cholesterol and low saturated fats, but they may still contain trans fat.
"These crackers list only one gram of saturated fat on the label but when we sent it to the lab we found it had another two grams of trans fat so this product actually has three times as much bad fat than is listed on the label," Wootan said of the Triscuits.
The FDA is considering changing food labels to include trans fats, and 50 scientists from prominent universities have signed a letter supporting the label change. They claim trans fat labeling will save lives and save billions of dollars in health care costs. But some critics say there is no need to re-label foods.