Why are normal women ier than plastic models/movie stars/etc.?

Reflecting on the "gross" question I wonder why some men find the fake plastic barbie-girl attractive and why some men (or women for that matter) find normal women attractive? Are we programmed by media to feel that way? Do our childhood perceptions of the chase for beauty (plastic surgery, lipo, etc) imprint a sense of what is beautiful in us? Is there some evolutionary desire for 'perfection' at work? Does the individual's sense of "healthy" reflect in that choice?