Fat
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.
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.
Read more about this topic: Animal Nutrition
Famous quotes containing the word fat:
“The poet is he that hath fat enough, like bears and marmots, to suck his claws all winter. He hibernates in this world, and feeds on his own marrow.”
—Henry David Thoreau (1817–1862)
“The modern picture of The Artist began to form: The poor, but free spirit, plebeian but aspiring only to be classless, to cut himself forever free from the bonds of the greedy bourgeoisie, to be whatever the fat burghers feared most, to cross the line wherever they drew it, to look at the world in a way they couldn’t see, to be high, live low, stay young forever—in short, to be the bohemian.”
—Tom Wolfe (b. 1931)
“Outside every fat man there was an even fatter man trying to close in.”
—Kingsley Amis (b. 1922)