Healthy fats
Healthy fats can lower your risk of heart disease by reducing the total and low-density lipoprotein (LDL) cholesterol levels in your blood. Cholesterol, which your body produces for building cells, is the main substance in fatty deposits (plaques) that can develop in your arteries. Plaques that build up can reduce blood flow through your vessels, increasing your risk of heart disease and stroke.

One type of polyunsaturated fat, omega-3 fatty acids, may be especially beneficial to your heart. Omega-3s appear to decrease the risk of coronary artery disease. They may also protect against irregular heartbeats and help lower blood pressure levels.

Here are the differences as well as the best food sources of these healthy fats:

Monounsaturated fat remains liquid at room temperature but may start to solidify in the refrigerator. Foods high in monounsaturated fat include olive, peanut and canola oils. Avocados and most nuts also have high amounts of monounsaturated fat.

Polyunsaturated fat is usually liquid at room temperature and in the refrigerator. Foods high in polyunsaturated fats include vegetable oils, such as safflower, corn, sunflower, soy and cottonseed oils.

Omega-3 fatty acids are polyunsaturated fats found mostly in seafood. Good sources of omega-3s include fatty, cold-water fish, such as salmon, mackerel and herring. Flaxseeds, flax oil and walnuts also contain omega-3 fatty acids, and small amounts are found in soybean and canola oils.

Harmful fats

Saturated and trans fats are less healthy kinds of fats. They can increase your risk of heart disease by increasing your total and LDL ("bad") cholesterol. Dietary cholesterol isn't technically a fat, but it's found in food derived from animal sources. Intake of dietary cholesterol increases blood cholesterol levels, but not as much as saturated and trans fats do, and not to the same degree in all people.

Here are how these fats differ and what their common food sources are:

Saturated fat. Usually solid or waxy at room temperature, saturated fat is most often found in animal products — such as red meat, poultry, butter, whole milk and half and half. Other foods high in saturated fat include coconut, palm and other tropical oils.

Trans fat. Also referred to as trans-fatty acids, trans fat comes from adding hydrogen to vegetable oil through a process called hydrogenation. This makes the fat more solid and less likely to spoil. Hydrogenated fat is a common ingredient in commercial baked goods — such as crackers, cookies and cakes — and in fried foods, such as doughnuts and french fries. Shortenings and some margarines also are high in trans fat. Food manufacturers are required to list trans fat content on nutrition labels. Amounts less than 0.5 grams per serving are listed as 0 grams trans fat on the food label.

Dietary cholesterol. Your body naturally manufactures all of the cholesterol it needs, but you also get cholesterol from animal products, such as meat, poultry, seafood, eggs, dairy products, lard and butter.

source: mayo clinic