Fats are a type of lipid that provide energy but do not dissolve in water. They are made of carbon, hydrogen and oxygen. Fats can come from animal sources like meat and dairy or plant sources like seeds, fruits and nuts. There are different types of fats including saturated, monounsaturated, polyunsaturated and trans fats. A balanced diet should limit saturated fats and include unsaturated fats to support health and reduce disease risk.