Stuff You Should Know About Fat:
There are two dominant forms of fat in the body known as the "Cis" and the "Trans form." Food and body-fats exist principally in the "Cis" forms. This is an important point although a little mysterious. In the manufacture of vegetable shortenings and margarines, some, but not all, of the oil bonds are hydrogenated. They are thus changed from their origin- “Cis form” to a “trans form.” Both forms are utilized in the body. But, the Cis form may be better utilized.
Hydrogenation also reduces the linoleic acid content of the fat. These changes have significance in digestion and are believed to affect the rate and manner in which fat is accepted and used in the body. The body does only one of two things with fats. It either stores fat or converts fat to energy.