What are trans fats?
There are two broad types of trans fats found in foods: naturally-occurring and artificial trans fats. Naturally-occurring trans fats are produced in the gut of some animals and foods made from these animals (e.g., milk and meat products) may contain small quantities of these fats. Artificial trans fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid.
The primary dietary source for trans fats in processed food is “partially hydrogenated oils.” Look for them on the ingredient list on food packages. In November 2013, the U.S. Food and Drug Administration (FDA) made a preliminary determination that partially hydrogenated oils are no longer Generally Recognized as Safe (GRAS) in human food.