A kind of fat in which one or more pairs of electrons in the atoms making up the fat molecule form a bond with a pair of electrons from another atom (a double bond). There are two kinds of unsaturated fats: monounsaturated, which contain one double bond; and polyunsaturated, which contain two or more double bonds. Monounsaturated fats are found in peanuts, peanut butter, olives, and avocados. Polyunsaturated fats, which are usually liquid at room temperature, are found in oils such as corn, sunflower, and soybean.
Note: Unsaturated fats are generally regarded to be healthier in the diet than saturated fats because they may help lower the level of cholesterol in the blood.