I'm not sure how a pill could be the equivalent of 1500 calories. That doesn't make sense to me and that article didn't link to any information explaining that claim.

However, zyprexa is definitely a notorious weight gainer. Honestly if you're not suffering from manic symptoms I wouldn't want to be on any antipsychotic. Maybe try a mood stabilizer like lamictal, which helps with depression. But that's just me. Zyprexa is pretty much the only atypical AP that I have not tried so I honestly can't comment on its effectiveness vs. side effects.