"I don't understand how anyone can be that fat and not shatter their own skeleton.
I would expect broken hips, shoulders, ribs, etc."
One would think, but then, they don't move a whole lot.
They have a whole slew of health issues from their bedridden state and size, that are pretty nasty and not much fun to talk about. They're basically rotting in place, and it's not pretty. Plus, hygeine is pretty much impossible at that size, I'll let you do the math.
These people always have someone who feeds them. I had a patient that weighed about 600 lbs and her family caretaker would give her an electric skillet that she would fry her own food in bed!!!!!!!!!!!!