Here is a link that I believe is a much more reliable source for those of you who are wondering if margarine really is only one molecule different from plastic.
It is written by a professor of chemistry. I cross checked to be certain that this man was real, and had actual certifications. He does, and you can do the same simply by searching his name on the internet. I heard this same rumor myself, one should really check into what they're reading, especially on the internet where so much information is completely unreliable.
http://www.madsci.org/posts/archives/2004-01/1074274923.Ch.r.htmlThank you.