It's easy to laugh at this film, because the jokes are so broad, but it's equally easy to be offended. The issue I have with the movie is that, in the course of making the point that we should see the inner-beauty in fat people, the Farrellys are implying that by being overweight you are universally ugly. In fact, in the world of Shallow Hal, if you are fat, you are a well-meaning mammoth who couldn't possibly be fancied unless under hypnosis or after an epiphany.
The movie also seems to suggest that the friends of fat people are ugly, and that uglies keep each other's company because no one else will want to associate with them, which is another reinforcement of social divisions. All of Rosemary's (Paltrow) friends are, as we see at the end, equally fat or gross or otherwise physically undesirable. Most disturbingly, the Farrellys undermine the inner-beauty point they've spent $40 million trying to make through Hal, because Hal's friends betray the judgmental reality. When his buddies see Rosemary for what she is, i.e. grossly fat, they are universally horrified in a "what are you doing with her?" way, which carries a more powerful punch than any of the tepid attempts to suggest she's beautiful because of her personality (moulded, we are told, by years of personal abuse because of her size).
The overall message is correct - inner beauty is ultimately what counts, because a sparkling character will outlast youthful good looks by decades. But the Farrelly's have approached the subject in a way that actually insults, rather than genuinely educates. It's not going to uplift anyone who's overweight, it'll just depress them. The majority of the film perpetuates the idea that being fat or ugly makes you a pariah or the object of sympathy or vulgar fascination.
There are some sweet moments, and a few laughs, so the movie's not a wholly worthless experience. But in the process of making its (valid) point it reinforces, rather than rejects, stereotypes.
