Function
Fats contain nine calories per gram and are one of the three main energy providing macronutrients of food, the other two macronutrients being carbohydrates and protein. Fats store energy, provide insulation for vital organs, and help start chemical reactions that control growth, immune functions, and reproduction. Fats enable the body to absorb, store, and transport the fat-soluble vitamins A, D, E, and K which are necessary to regulate blood pressure, heart rate, blood clotting, and the nervous system.
Cholesterol, a type of fat, is used to build cells, hormones, and vitamin D. Cholesterol travels through blood in small packages called lipoproteins, consisting of fat (lipid) on the inside and either of two kinds of proteins, low-density lipoproteins (LDL) and high-density lipoproteins (HDL), on the outside. A healthy level of both types of proteins is important, as high LDL(“bad” cholesterol) leads to a buildup of cholesterol in arteries and increases the risk of heart disease. Since it helps remove excess cholesterol from the blood, HDL is referred to as “good” cholesterol. Triglycerides, a kind of fat, store unused calories and provide the body with energy. A high triglyceride level may contribute to the thickening of artery walls which increases the risk of a heart attack. LDL and Triglyceride levels can be reduced by losing weight, reducing the intake of calories, avoiding simple carbohydrates, consuming healthier kind of fats, and exercising regularly.
Saturated fat, trans fat, monounsaturated fat, and polyunsaturated fat are the four major dietary fats. The bad fats, saturated fat and trans fat, raise LDL levels. On the other hand, polyunsaturated fat, a type of good fat, lowers both LDL and HDL levels. Monounsaturated fat, another kind of good fat, only reduces LDL cholesterol. Cooking oil, ghee, and butter are major sources of fat and consist of saturated fat, polyunsaturated fat, and monounsaturated fat. Ghee, butter, coconut oil, and palm oil, however, have a higher saturated fat content. Sunflower oil, safflower oil, corn oil, cottonseed oil, and soya bean oil contain a great amount polyunsaturated fat. Groundnut oil, mustard oil, canola oil, and olive oil have a higher monounsaturated fat content.