Definition for View source for Trans fat

Trans fat is the common name for unsaturated fat with trans-isomer (E-isomer) fatty acid(s). Because the term describes the configuration of a double carbon–carbon bond, trans fats are sometimes monounsaturated or polyunsaturated, but never saturated. Trans fats occur during the processing of polyunsaturated fatty acids in food production. In the vegetable and animal kingdoms, fatty acids generally have cis (as opposed to trans) unsaturations.