|Fats| provide energy by furnishing calories to the body, and by carrying |Vitamins| A, D, E and K. They are the most concentrated source of energy in the diet. |Fats| supply 9 calories per gram; |carbohydrates| and |proteins| have 4 calories per gram. In addition to storing energy, |fats| are necessary to maintain healthy skin and hair, regulate levels of ~cholesterol~ in the ~blood~, supply "essential" fatty acids (those the body cannot make and must get from food), and for the promotion of satiety (slowing the emptying of food from the |stomach|).
All |fats| are a combination of saturated and unsaturated fatty acids. Highly saturated |fats| are usually solid at room temperature and keep well. |Fats| that are highly saturated come chiefly from animal sources and include butter, milk fat, the fat in meats, and coconut and palm |oils|. Unsaturated fatty acids are generally liquid at room temperature. Examples of these include olive, peanut, canola, avocado, corn, safflower and sesame |oils|. A process called hydrogenation adds hydrogen atoms to unsaturated |fats| to make them harder and more stable. Generally, artificially saturated vegetable |fats| are no better for you than saturated animal |fats|.
Fat sources are butter, margarine, salad |oils|, |nuts|, cream, egg yolks, most cheese, lard, and meat. The important dietary unsaturated |fats| come from plants and fish. A healthy source of fat is from fresh fish, such as salmon or mackerel. These are an excellent source of ~omega-3s~, which significantly reduce ~blood~ clotting and may also prevent hardening of the arteries. Two to three servings of fresh fish per week is recommended.
