When grocery shopping, seeing a zero next to the trans fat is usually a good thing, right? Not necessarily.
According to a study from the Centers for Disease Control and Prevention, one out of every 10 packaged foods contains partially hydrogenated oils, a main source of trans fat.
Trans fat is a fat formed when hydrogen is added to liquid oil to turn it into fat.
In the study, published in Preventing Chronic Disease, researchers found that 84 percent of packaged foods that contained partially hydrogenated oils advertised 0 grams of trans fat. The researchers examined a total of 4,340 popular packaged items.
"Our analysis demonstrates that industrial trans fat is still common in US packaged foods, particularly in some food categories," said the research team in a statement.
The FDA requires that food with less than 0.5 g of trans fat per serving must be labeled as 0 g 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," wrote researchers in their study.
The American Heart Association suggests that consumers cut back on as many foods as they can with partially hydrogenated vegetable oils.
The FDA recently announced that it had determined that partially hydrogenated oils were not "generally recognized as safe."
People who consume trans fats are at a higher risk for cardiovascular issues and diabetes.
Up until 1990, very little research had been done on trans fats and their effects on health, but in the 1990s, researchers began to look closer into trans fats and identify their health risks. Motivated by the research, the FDA began requiring that companies label the trans fats in their foods.
Trans fats are not usually found naturally in foods, but there has not been sufficient evidence to determine whether naturally-occurring trans fats have the same negative effects on cholesterol levels as industrially-produced trans fat.
Trans fat is found in many fried and baked foods. The AHA recommends consumers cut back on their intake of these products in favor of fruits, vegetables, whole grains and other low-fat dairy products.
It also recommends that consumers use soft margarine as a substitute for butter and to use the liquid or tub varieties over the stick forms.