Fat is an essential nutrient that our body needs – it plays an important role in functioning as an energy store, a cushion for our vital organs and a transport system for fat-soluble vitamins (A, D, E and K). Hence, we require some fat in our diet. However, we should also bear in mind that fat is a concentrated source of calories (9kcal/g compared to 4kcal/g for carbohydrate and protein) – high consumption of fats may lead to weight gain and obesity. Therefore, in order to make wise dietary choices, let us learn more about good and bad fats!
So what kind of fats are there?
There are four different types of fat – saturated fat, monounsaturated fat, polyunsaturated fat and trans fat. Fats and oils in food exist in a mixture of saturated and unsaturated fats. Bad fats include trans fat and saturated fat. Trans fats can be found in industrially produced vegetable fats and oils – whereby they undergo hydrogenation, which hardens the liquid oil to produce fats like hard margarine and shortening. Minute quantity of these fats can also be found in milk and other meat products. Trans fat raises our LDL (bad) cholesterol and lowers our HDL (good) cholesterol levels – this leads to an increased risk of developing heart disease and stroke. Some main sources of trans fat in our diet include deep-fried foods, baked goods like pastries, cookies and cakes.
Similarly, a diet high in saturated fats raises our LDL cholesterol levels, leading to increased risk of heart diseases and stroke as well. Saturated fats occur naturally in many foods. Major food sources come from animal sources including meat and dairy products – lard, poultry with skin, full cream milk, butter, cheese, and food prepared with palm-based vegetable oil.
Good fats include poly- and mono-unsaturated fats. Oils rich in polyunsaturated fats provide essential fats that our body needs but cannot produce itself – omega-6 and omega-3 fatty acids (FA). Omega-3 FA lowers the risk of heart diseases by reducing blood clotting within the arteries and hardening of the arteries. Foods rich in omega-3 FA includes fatty fishes like salmon and sardine, walnuts, soybean and canola oils. Omega-6 FA also helps to improve heart health by reducing our LDL cholesterol levels in the blood. Foods rich in omega-6 include seeds like sunflower and sesame seeds, as well as soybean and sunflower oil.
Besides polyunsaturated fats, monounsaturated fats can help to reduce bad cholesterol levels in our blood as well. This in turns lowers the risk of developing heart diseases and stroke. Good sources of monounsaturated fats include olive oil and sesame oil. In order to maintain a healthy diet, we should aim to consume fat in moderation. Having too much fat, even the good types, will provide excess calories – remember that ALL fats provide 9kcal/g. We should limit the intake of saturated and trans fats in our diet, and replace them with unsaturated fats.