Trans fat, also known as hydrogenated vegetable oil, trans fatty acid, vegetable shortening, margarine, etc., is a kind of unsaturated fat containing trans-configuration fatty acid, which is produced mainly through hydrogenation by microorganisms or industrial processes, high temperature refining and repeated frying of fats. The trans-fat derives its name from its chemical structure. The molecule contains a reverse covalent bond structure on opposite sides of the carbon atom, which makes it stable, resistant to high temperatures and storage. It can be used to improve the taste, make cookies, bread, French fries and other foods crispy and pleasantly soft, and also improve the appearance of food. It is more common in daily diet and is mostly used in margarine, margarine and other vegetable butters, fried foods such as potato chips and fries, desserts such as egg tarts and cream cakes, and food oils used for spreading, baking and frying. Food packaging labels that contain hydrogenated vegetable oil, partially hydrogenated vegetable oil, hydrogenated fat, solid vegetable oil, ghee, margarine and other ingredients, indicating the presence of trans fats. For example, long-term use of trans fats may increase blood lipids, increase the risk of blood clots, affect fetal and adolescent central nervous growth and development, increase the possibility of dementia and depression, and cause obesity, promote inflammation and increase the risk of diabetes. Therefore, it is recommended to minimize the intake of such foods in daily life.