The fat breakdown
All fats supply the same amount of kilojoules to the body (1g of fat provides 37kJ); however, they’re not all bad for you. Fats are the body’s most concentrated source of energy (in comparison, 1g of protein provides 17kJ and 1g of carbohydrate provides 16kJ) and help protect and insulate your vital organs. They also allow fat-soluble vitamins (A, D, E and K), to be absorbed and provide essential fatty acids, which are important building blocks for the brain, eyes and nervous tissues. It’s generally recommended that less than 30% of your daily kilojoule intake should come from fat, with no more than 10% coming from saturated fat.
Saturated fat is the main dietary cause of high cholesterol, raising levels of the harmful low-density lipoprotein (LDL) cholesterol in the blood. Too much saturated fat heightens your risk of heart disease.
Trans fat behaves similarly to saturated fat. However, it not only raises levels of harmful LDL cholesterol, but also lowers levels of the good high-density lipoprotein (HDL) cholesterol. To earn the Heart Foundation tick, vegetable oils must contain no more than 1% trans fat as part of their total fat content.
Monounsaturated and polyunsaturated (omega-3 and omega-6) fats are the types you should aim to include in your diet. They’re essential nutrients for the body, and also reduce the levels of the harmful LDL cholesterol. Keep in mind, however, that these fats are still high in kilojoules, so only use them in moderation.
When it comes to cooking, a small amount of the right oil can make your meals heart-friendlier. You can avoid the bad fats – saturated and trans – by staying away from processed and fast foods, while cooking with the right oils (instead of butter or margarine), adding nuts and seeds to stir-fries and salads, and including avocados in your diet will provide your body with the good monounsaturated and polyunsaturated fats it needs. See The Good and Not-so-Good Oils, for more.