The oil derived from a process of chemically changing liquid oil from a saturated fat into a stiffer and more stable form, such as occurs by changing a vegetable oil into a stick of margarine. This process produces trans fatty acids in the resulting food product. Also known as trans fat, this is a type of fat that is created when oils are partially or fully hydrogenated. Any foods containing hydrogenated oil will contain trans fatty acids. Food and medical researchers believe there is evidence that supports the theory that the consumption of trans fatty acids will decrease the beneficial effects of good HDL cholesterol and instead, produce more bad LDL cholesterol.