All foods contain a mixture of the three different types of fats: saturated, polyunsaturated and monounsaturated. There are no foods that contain only one type. They contain the three types of fat in varying proportions, and the type that occurs in the largest percentage is used to name that fat. For example, olive oil is called a monounsaturated fat because it contains more monounsaturated fat than polyunsaturated or saturated, but it has some of all three types.

SATURATED FATS: These fats are solid at room temperature. When you take in more calories than your body needs, saturated fats raise cholesterol and increase risk for heart attacks. Large amounts of saturated fats are found in butter, meats and high-fat dairy products.

MONOUNSATURATED FATS are liquid at room temperature. They are found in all food sources of fats, but particularly rich sources include olives, almonds and other seeds. Before the bad LDL cholesterol can form plaques in arteries, it must first be converted to oxidized LDL. Monounsaturated fats are thought to stabilize the bad LDL cholesterol and make it less likely to form plaques in arteries. Recent studies suggest that their heart-health benefits may come from antioxidants and other phytochemicals found in the seeds as well.

POLYUNSATURATED FATS are healthful as long as they are left in their natural state, which is liquid at room temperature, and not converted to the more solid partially hydrogenated oils (see below). Polyunsaturated fats include the essential fatty acids (omega-3