Hydrogenated fat is where vegetable oil is heated under high pressure to make it solid. It is used because it extends a products shelf life, improves texture, is easy to work with and is cheap. On food labels it may be called vegetable shortening, vegetable fat or oil. Margarine has a high quantity of hydrogenated fat. Hydrogenated fat is not a good fat to be feeding our bodies. It offers little nutrients to our cells and in fact it destroys the essential fatty acids (EFAs) we need to function well in both a physical and mental capacity. When heating the vegetable oil to turn it into hydrogenated fat, hydrogen gas and nickel or copper is added which replaces the EFAs with saturated and trans fatty acids.
Saturated fats like butter and coconut should be kept to a minimum in the diet. Trans fatty acids are unnatural and compete with the EPAs to be absorbed. They lower good cholesterol, and increase bad cholesterol, which attributes to the clogging of arteries.
When it comes to cosmetic and skin care products the BDIH state that fully hydrogenated oils are ok as they do not contain trans fatty acids. Conventional beauty products use mineral oils instead to create stability and consistency in a product, and these have far harsher effects to our heath.
The good news - there are alternatives such as coconut or palm fat, which harden naturally at room temperature. But they are in a lot of processed foods so read packets carefully if you want to avoid this nutrient-zapping ingredient.