Functions of Fats:

• Fat is one of the 3 nutrients (along with protein and carbohydrates) that supply calories to the body. Fat provides 9 calories per gram, more than twice the number provided by carbohydrates or protein.
• Fat is essential for the proper functioning of the body. Fats provide essential fatty acids, which are not made by the body and must be obtained from food. The essential fatty acids are linoleic and linolenic acid. They are important for controlling inflammation, blood clotting, and brain development.
• Fat serves as the storage substance for the body's extra calories. It fills the fat cells (adipose tissue) that help insulate the body. Fats are also an important energy source. When the body has used up the calories from carbohydrates, which occurs after the first 20 minutes of exercise, it begins to depend on the calories from fat.
• Healthy skin and hair are maintained by fat. Fat helps the body absorb and move the vitamins A, D, E, and K through the bloodstream.

Types of Fats:

Saturated Fats:

These are the biggest dietary cause of high LDL levels ("bad cholesterol"). When looking at a food label, pay very close attention to the percentage of saturated fat and avoid or limit any foods that are high. Saturated fat should be limited to 10% of calories. Saturated fats are found in animal products such as butter, cheese, whole milk, ice cream, cream, and fatty meats. They are also found in some vegetable oils -- coconut, palm, and palm kernel oils. (Note: Most other vegetable oils contain unsaturated fat and are healthy).

Food Sources:

• meat
• butter
• cream
• cheese
• eggs
• lard
• full fat milk
• suet and dripping
• full fat yoghurt.

Saturated fats are also found in hard margarines that are formed by the 'hydrogenation' of vegetable oils. Hydrogenation increases the shelf-life of food, but it also creates trans fats (trans-fatty acids) that are harmful for health. Hydrogenated margarine or butter is often used for making cakes, biscuits and pastry.

Uunsaturated Fats:

Fats that help to lower blood cholesterol if used in place of saturated fats. However, unsaturated fats have a lot of calories, so you still need to limit them. Most (but not all) liquid vegetable oils are unsaturated. (The exceptions include coconut, palm, and palm kernel oils.) Unsaturated fats contain essential fatty acids that cannot be manufactured by the body. This means you need to get them from food.
There are two types of unsaturated fats:

• Monounsaturated fats: Examples include olive and canola oils.
• Polyunsaturated fats: Examples include fish, safflower, sunflower, corn, and soybean oils.

Food Sources:

Good sources of unsaturated fats include:

• avocados (one quarter of an avocado contains 5g of unsaturated fat)
• unsalted nuts (cashew, brazil, pecan, walnut)
• seeds (pumpkin, sunflower, sesame).
• Omega-3 and omega-6 essential fatty acids play an important role in the functions of the body that promote health and wellbeing.

In particular, studies have shown that omega-3 fatty acids protect against heart disease. Oily fish is the best source of omega-3:

• Salmon
• Tuna
• Trout
• Sardines
• Mackerel
• Pilchards
• Herring.

Current advice is to eat oily fish two to three times a week. While oily fish is the best source of essential fatty acids, other omega-rich foods are:

• Corn oil
• Flaxseed oil
• Nut oil
• Safflower oil
• Sunflower oil

Transfats:

Trans-fats are also known as partially hydrogenated vegetable oils. They lower “good” cholesterol (HDL) and raise “bad” cholesterol (LDL.).

This type of fat is not a saturated fat, and it is found in baked goods, food at most restaurants and in fast-food chain foods. Trans-fat is the result of a process called hydrogenation, or adding hydrogen to vegetable oil and making the fat more solid at room temperature. Some examples of foods high in Trans fats are: cookies, crackers, cakes, French fries, fried onion rings, and donuts.