Trans-fatty acids (TFA) are fatty acids with at least one double carbon–carbon bond in the trans configuration.
They occur naturally in meat and dairy products from ruminant sources (cows, goats and sheep, for example) in small amounts.
The biggest source of industrially-produced trans fats is partially hydrogenated oils (PHOs). This process transforms the oil into a solid fat, increases its shelf-life and enhances the texture of the finished food product.
PHOs are commonly found in products such as cookies, cakes, ice cream, margarine, microwave popcorn, instant pasta sauces and soups and low-quality oils.