Hey there Mr. Muscle.....
Good Question!
First, remember the difference in the chemical compostion between the two...mono-unsaturated fats contains one double bond and fatty acids that have multiple double bonds are called poly-unsaturated.
Basically, Poly-unsaturated fats cause less of a problem within the body and mono-unsaturated fats are considered to be the easiest fats to ingest and are also said to lower your cholestrol.
It is most important, however, that your body is ingesting the essential fatty acids that it cannot manufacture. Because your body cannot manufacture them, they must come in from the food you eat.
Essential fatty acids fall into two groups: omega-3 and omega-6. (The 3 and 6 refer to the first carbon double bond position on the fatty acid chain.)
All essential fatty acids are polyunsaturated, so the 3 and the 6 mean that the first double bond is either 3 or 6 carbons in from the end.
I know this is long and I hope not to confusing ...but, it is most important that your body is getting the fatty acids that it needs...then focus on ingesting mono-unsaturated fats.
~toga