Hydrogenated oils are important for cooking and as an ingredient in many products. Hydrogenated vegetable oil is a type of fat known as a trans fat and should be avoided in a diet. Trans fats have been heated and can be toxic to the body.
While fats that are essential fatty acids, such as butter or coconut oil, are beneficial for the body, trans fat oils, according to Treelight, are poisonous to the body.
Hydrogenation causes oils to change their structure and changes an oil’s action. It no longer acts to assist metabolism and can actually cause a person to gain weight. Additionally, excessive consumption of hydrogenated oils can cause allergies and contribute to diseases such as multiple sclerosis.
Many types of foods contain hydrogenated oils, including cookies, potato chips and peanut butter, according to Treelight. Hydrogenated oil comes from soybean oil, which lowers energy levels. Soybean oil lowers metabolism by depressing the thyroid.
One of the most popular types of hydrogenated oils is vegetable oils. These types of oil can be used in moderation for cooking because they are inexpensive and have a high flash point.
Wikipedia also points out that vegetable oils are used for soaps, perfumes, cosmetics, pet food additives and biodiesel fuels.