P>Cottonseed oil is one of the most widely used oils, added to many processed foods, such as cereals and potato chips. It is relatively inexpensive and is readily available. Yet, it merits its place on our list of worst oils for several reasons. Cotton is a crop that is heavily sprayed with pesticides, so cottonseed oil may be loaded with pesticides. And, like tropical oils, cottonseed oil is low in monounsaturated fats and high in saturated fats. Also, cottonseed oils are likely to be hydrogenated to further extend its shelf life.