The body can integrate most of the fats it needs from the diet. However, two essential fatty acids, linoleic and alpha-linolenic, cannot be synthesized in the body and must be acquired from food. These basic fats, found in plant foods, are used to build specialized fats called Omega-3 and Omega-6 fatty acids.
In chemistry, and especially in biochemistry, a fatty acid is a carboxylic acid with a long aliphatic tail, which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from triglycerides or phospholipids. When they are not attached to other molecules, they are known as “free” fatty acids.