Like carbohydrates, oils and fats are made up of carbon, hydrogen, and oxygen atoms.
However the ratio of these three elements is different.In both plants and animals, oils and fats provide important
reservoirs of stored energy. Because they contain more than twice as many calories per
gram as do carbohydrates or protein, oils and fats are concentrated energy supplies. While
carbohydrates, and especially simple sugars, are immediate sources of energy, oils and
fats take longer to metabolize and are used for long-term storage.
Most important oils come from seeds. Your grocery store
probably stocks a number of cooking oils that are extracted from seeds. Examples include
corn, soybean, sunflower, safflower, sesame, peanut, and canola oils. (Canola oil is
extracted from rapeseed, Brassica napus.)
Counting Calories. Oils and fats contain 9 calories
per gram. Carbohydrates and proteins both contain 4 calories per gram.
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Oil or Fat?
Fats in a liquid state are called oils. In common usage, fats are solid at room
temperature; oils are liquid at room temperature. Margarine and Crisco (shortening) are
made by "hydrogenating" liquid oils to make them solid at room temperature. |
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