Fats are referred to in the plural because there is no one type of fat. Fats are composed of the same three elements as carbohydrates -- carbon, hydrogen and oxygen, However, fats have relatively more carbon and hydrogen and less oxygen, thus supplying a higher fuel value of nine calories per gram (versus four calories per gram from carbohydrates and protein). One molecule of fat can be broken down into three molecules of fatty acids and one molecule of glycerol. Thus, fats are known chemically as triglycerides. Fats are a vital nutrient in a healthy diet. Fats supply essential fatty acids, such as linoleic acid, which is especially important to childhood growth. Fat helps maintain healthy skin, regulate cholesterol metabolism and is a precursor of prostaglandins, hormone-like substances that regulate some body processes. Dietary fat is needed to carry fat-soluble vitamins A, D, E and K and to aid in their absorption from the intestine.