However, fats have relatively more carbon and hydrogen and less oxygen, thus supplying the higher fuel value of nine calories per gram. Fats are actually combinations of many different fatty acids, each exerting characteristic physiological and metabolic effects. These fatty acids are generally classified as saturated, monounsaturated or polyunsaturated. These terms refer to the number of hydrogen atoms attached to the carbon atoms of the acid chains in the fat molecule. Saturated fatty acids are more stable than unsaturated fatty acids because of their chemical structure.
Stability is especially important in cooking oil to prevent rancidity and off flavors or odors.
Fat is an important ingredient in many foods because of its functional properties. In many recipes, fat enhances the taste, aroma and texture of the food. Because it is digested more slowly than protein or carbohydrates, it also plays an important role in satiety, providing a sense of fullness after eating. Contrary to popular belief, most of the cholesterol found in the blood is manufactured by the body itself, not derived through foods consumed in the diet. Dietary cholesterol is found only in animal foods such as egg yolks, organ meats, beef, chicken and in low amounts in shellfish.