<prompt> Trans fatty acids are known to form duringHydrogenation of oilsBeta oxiation of palmitateRancidity of fatsProstaglandin biosynthesis  <response>: Trans fatty acids TFA are atherogenic. They lower the HDL level and elevate LDL level. TFA is present in dairy products and hydrogenated edible oils. It is widely used in the food industry since it increases the shelf life of fried food. Cooking media containing PUFA and fast food preparations have a high content of trans fatty acids. Trans fatty acids adversely affect endothelial function and aggravate insulin resistance and diabetes. It is high in processed foods and bakery products, where hydrogenated vegetable oils are used for cooking.Ref: DM Vasudevan - Textbook of Biochemistry, 8th edition, page no: 437 