<Tr> <Td> </Td> <Td> This article duplicates the scope of other articles, specifically, Human nutrition #Fat . Please discuss this issue on the talk page and edit it to conform with Wikipedia's Manual of Style . (March 2013) </Td> </Tr> <P> A molecule of dietary fat typically consists of several fatty acids (containing long chains of carbon and hydrogen atoms), bonded to a glycerol . They are typically found as triglycerides (three fatty acids attached to one glycerol backbone). Fats may be classified as saturated or unsaturated depending on the detailed structure of the fatty acids involved . Saturated fats have all of the carbon atoms! in their fatty acid chains bonded to hydrogen atoms, whereas unsaturated fats have some of these carbon atoms double - bonded, so their molecules have relatively fewer hydrogen atoms than a saturated fatty acid of the same length . Unsaturated fats may be further classified as monounsaturated (one double - bond) or polyunsaturated (many double - bonds). Furthermore, depending on the location of the double - bond in the fatty acid chain, unsaturated fatty acids are classified as omega - 3 or omega - 6 fatty acids . Trans fats are a type of unsaturated fat with trans - isomer bonds; these are rare in nature and in foods from natural sources; they are typically created in an industrial process called (partial) hydrogenation . </P> <P> Many studies have shown that unsaturated fats, particularly monounsaturated fats, are best in the human diet . Saturated fats, typically from animal sources, are next, while trans fats are to be avoided . Saturated and some trans fats are typically solid at room temperature (such as butter or lard), while unsaturated fats are typically liquids (such as olive oil or flaxseed oil). Trans fats are very rare in nature, but have properties useful in the food processing industry, such as rancid resistance . </P> <P> Most fatty acids are non-essential, meaning the body can produce them as needed, generally from other fatty acids and always by expending energy to do so . However, in humans at least two fatty acids are essential and must be included in the diet . An appropriate balance of essential fatty acids ---omega - 3 and omega - 6 fatty acids ---seems also important for health, though definitive experimental demonstration has been elusive . Both of these "omega" long - chain polyunsaturated fatty acids are substrates for a class of eicosanoids known as prostaglandins, which have roles throughout the human body . They are hormones, in some respects . The omega - 3 eicosapentaenoic acid (EPA), which can be made in the human body from the omega - 3 essential fatty acid alpha - linolenic acid (LNA), or taken in through marine food sources, serves as a building block for series 3 prostaglandins (e.g. weakly inflammatory PGE3). The omega - 6 dihomo - gamma - linolenic acid (DGLA) serves as a building block for series 1 prostaglandins (e.g. anti-inflammatory PGE1), whereas arachidonic acid (AA) serves as a building block for series 2 prostaglandins (e.g. pro-inflammatory PGE 2). Both DGLA and AA can be made from the omega - 6 linoleic acid (LA) in the human body, or can be taken in directly through food . An appropriately balanced intake of omega - 3 and omega - 6 partly determines the relative production of different prostaglandins: one reason a balance between omega - 3 and omega - 6 is believed important for cardiovascular health . In industrialized societies, people typically consume large amounts of processed vegetable oils, which have reduced amounts of the essential fatty acids along with too much of omega - 6 fatty acids relative to omega - 3 fatty acids . </P>

Which trace mineral is required for the function of perhaps more proteins than any other mineral