A concentrated source of food energy containing 9 calories per gram. In addition to supplying energy, fat aids in the absorption of certain vitamins; enhances flavor, aroma and mouthfeel of food; and adds satiety to the diet. Fatty acids, the basic chemical units of fat, are either saturated, monounsaturated or polyunsaturated.
Saturated fatty acids are found primarily in fats of animal origin (meat, poultry, fish, seafood, milk and their products) and are usually solids at room temperature. Exceptions are some vegetable oils (palm, palm kernel and coconut) which contain large amounts of saturated fatty acids. Saturated fatty acids increase blood cholesterol levels.
Monounsaturated fatty acids are found in fats of both plant and animal origin and tend to improve blood cholesterol levels. Polyunsaturated fatty acids are found primarily in fats of plant origin and in fats of fatty fish and also tend to improve blood cholesterol levels. When monounsaturated or polyunsaturated fats are chemically hydrogenated, they become more solid trans-fatty acids. Trans-fatty acids tend to increase the levels of harmful LDL (low-density lipoprotein) cholesterol and decrease the levels of helpful HDL (high-density lipoprotein) cholesterol in the blood.
Most nutrition professionals recommend that we reduce our total dietary fat to 30% or less of total calories and that we limit our saturated fat intake to less than 10% of total calories. They emphasize that most of the fat in our diets should come from monounsaturated and polyunsaturated fats, including omega-3 fatty acids.
A large egg contains about 5 grams of fat – about 1.5 grams saturated and 2.6 grams unsaturated – and is considered a medium-fat food. You can keep added fats, especially saturated fats, to a minimum by using low-fat cooking methods and serving eggs with fruits, vegetables, whole-grain foods and low-fat milk products.
– See Cholesterol, Cooking Methods, Omega-3 Fatty Acids