Definition: Unsaturated fats are a family of fatty acids.
In unsaturated fats, the the carbon backbone of the fatty acid chain includes least one double bond. (Carbon atoms can bind together by either single or double bonds.) If the unsaturated fat has only one double bond, it is called a monounsaturated fat. If it contains more than one double bond, it is called a polyunsaturated fat.
Depending on the geometry of the double bond, unsaturated fatty acids can exist in either a cis or trans forms. Cis and trans fatty acid chains assume very different shapes (cis fatty acids are bent, while trans fatty acids are straight), and have different effects on the body.
Cis fatty acids occur widely in nature, and are found widely in plant foodsources. Many unsaturated fatty acids found in natural sources are essential to normal health. These include the essential omega-3 fatty acids.
Trans fatty acids in the diet are almost exclusively man-made, and in recent years have been found to be associated with increased cardiovascular risk.
