Fats

Fats have several roles in the diet. The two main groups of nutrients that fats offer are the fat soluble vitamins and the essential fatty acids. Fats are found in both plant and animal foods and make foods easier to chew and swallow. The fat soluble vitamins A, D, E and K are found in the fatty parts of food and so diets very low in fats can be low in these vitamins.

There are three main classes of fats: saturated, monounsaturated and polyunsaturated. Omega 3 and omega 6 fatty acids are mostly found in polyunsaturated fats and are important for the body's development. They play a role in reducing inflammation, this can help protect against cancer, arthritis, heart disease and diseases of the immune system.

Fats offer a concentrated source of energy, providing more than twice as much energy as the same weight of carbohydrate or protein. Regardless of the type or source, fats all contain around the same number of calories. Whilst it is essential to consume fats, a high saturated fat diet can lead to obesity because fatty foods are so rich in energy (kilojoules). Obesity and a high intake of saturated fat can also increase your risk of disorders such as heart disease, diabetes and cancer.

Saturated Fats (hard fats) and Trans Fatty Acids

Saturated Fats are found in animal foods, such as meat, butter and cheese, and plant foods such as coconut and palm oil. Trans fatty acids are unsaturated fats that have undergone a chemical process called hydrogenation to turn them into a type of saturated fat. They are found in packaged foods such as pastries, biscuits, crackers and baked goods. High intakes of saturated fats and trans fatty acids are associated with an increased risk of many diseases including heart disease and cancer. As little dietary fat as possible should come from these fats (maximum 10% of your daily intake of fats).

Monounsaturated Fats

These include canola, olive, macadamia and peanut oils and are also found in avocados. Monounsaturated fats have been shown to help to lower cholesterol and decrease blood clotting. They are also more stable in cooking compared to polyunsaturated fats, and on exposure to air, and therefore are less likely to form trans fatty acids.

Polyunsaturated Fats

These are found in oils of plant origin such as safflower, sesame, sunflower and corn and may help to lower cholesterol and decrease blood clotting, thus reducing the risk of heart disease. However, polyunsaturated oils can change under certain conditions for example exposure to air and with high temperatures in cooking and food processing to form trans fatty acids. A high intake of polyunsaturated fats has been linked to an increased risk of cancer when vitamin E intake is inadequate.

Omega-3 and Omega-6 Fatty Acids

Essential fatty acids are involved in energy production, the transfer of oxygen from the air to the bloodstream, and the manufacture of haemoglobin (transports oxygen to our muscles). They are also involved in growth, cell division and nerve function. Essential fatty acids are found in high concentrations in the brain and are essential for normal nerve impulse transmission and brain function.

The body needs at least 25 grams of fat a day for good health, it is recommended that only 10% of this is saturated fat. Health authorities agree that up to 30% of energy from your diet can come from fats and oils. You can reduce the fat content in your diet by:

• using reduced fat dairy products
• trimming visible fat from meats
• removing the skin from chicken
• adding less fats and oils to your cooking
• using less processed meats eg sausages, devon and salami.

• polyunsaturated fats include: grapeseed, linseed, safflower, soybean and walnut oils
• monounsaturated fats include: almond, hazelnut, olive, canola and peanut oils.

The highest sources of unhealthy saturated fats are coconut and palm oil.

Are you eating too much fat?Find out now.