All oils are made up of three different types of fatty acids in varying proportions. The types are saturated, monounsaturated and polyunsaturated. Health experts have long advised people to choose oils low in saturated fat because it is linked to high cholesterol levels and cardiovascular disease.
Most common cooking oils are low in saturated fat, which is good news. (Palm oils and coconut oils are the high sat-fat exceptions.) Still, all oils are extremely concentrated in calories, so you'll want to use them carefully.