I guess point is, how tf is the normal idea of obese a 600lb bed-bound monster ?!?  Fat people.  Seriously.  They see themselves as normal and anyone around their size as normal.  And they tend to herd together, as all addicts do, so it seems normal to them.  Anyone larger is obese, but not them and their friends. And as the general population grows ever larger, so too does the perception of what size obeast is. We all know it's at BMI of 30, but try to bring empirical metrics to a dumb heffalump's attention and you will have a hard time of it.