Hydrogenated oils are synthetic oils made from unsaturated vegetable oils. Unsaturated oils are the healthier type of fat. The purpose of hydrogenation is to add more hydrogen to the chemical structure of unsaturated oils to reach a saturated state. ThisÂ process allowsÂ a change in the physical aspect of the oil from a liquid to a semi-solid or a solid state. However, hydrogenated oil is a major factor of multiple conditions including obesity, Alzheimer disease, and myocardial infarction. Unsaturated fat remains a healthier choice.