1 in 10 Packaged Foods Has Trans Fat

image shows a food label
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People may be consuming more trans fat than they think, as a result of misleading food labels, according to a study from the New York Department of Health and Mental Hygiene.     

Researchers examined 4,340 top-selling packaged foodsand found that 9 percent contained partially hydrogenated oils, the main source of trans fat. But of those foods, 84 percent claimed on their packaging to have "0 grams" of trans fat.

The amount of trans fat in these products varied from small traces to almost 0.5 grams of trans fat per serving, the researchers said. [5 Foods that Could Change Under a Trans Fat Ban]

Under the rules of the Food and Drug Administration, foods that contain less than 0.5 g of trans fat per serving must be labeled with "0 g" of trans fat.

"This labeling is cause for concern because consumers, seeing the 0 g trans fat on the nutrition facts label, are probably unaware that they are consuming trans fat," the researchers wrote in their study, published in the in the journal Preventing Chronic Disease.

Trans fat is a specific type of fat that is formed when hydrogen is added to liquid oils to turn them into solid fats. The FDA has tentatively determined that partially hydrogenated oils are not "generally recognized as safe" for consumption. If the FDA makes a final determination, trans fat would become an illegal food additive.

People who consume trans fat may be at higher risk for heart disease, stroke and diabetes, studies have suggested.

The food products examined in the study ranged from cookies to salad dressing and canned soup.

"Our analysis demonstrates that industrial trans fat is still common in U.S. packaged foods, particularly in some food categories," the researchers said.

For example, half of the foods in the potato chips category, and 35 percent of cookies contained trans fat, according to the report.

Email Bahar Gholipour. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

Bahar Gholipour
Staff Writer
Bahar Gholipour is a staff reporter for Live Science covering neuroscience, odd medical cases and all things health. She holds a Master of Science degree in neuroscience from the École Normale Supérieure (ENS) in Paris, and has done graduate-level work in science journalism at the State University of New York at Stony Brook. She has worked as a research assistant at the Laboratoire de Neurosciences Cognitives at ENS.