Trans fat, also known as trans fatty acid, is generally produced after hydrogenation of oil, such as hydrogenated oil and fried foods and baked foods made with trans fat.

Trans fatty acids are unsaturated fatty acids. Under high temperature conditions, their molecules contain reverse *** valence bonds located on opposite sides of the carbon atoms. The structure changes from cis to trans isomers. The longer the heating time, The more fats and oils with high melting points, such as margarine, are converted, the more trans fatty acids are produced. Excessive intake of trans fatty acids can increase the risk of cardiovascular disease because it will increase plasma total cholesterol levels, increase the levels of "bad for you" low-density lipoproteins and lipoprotein(a), and reduce the risk of cardiovascular disease. The amount of “good-for-you” HDL. Therefore, when buying food, you must read the ingredient list. You can check whether there is "partially hydrogenated vegetable oil" on the product nutrition label.