I printed out Meg's post and discussed it with the gals at work. It would be impolite to type what most of us thought.

Obviously the author has never nursed someone who is very over weight. Their troubles only multiply ... it matters not to me if the obesity caused the illnesses from which they suffer, they're going to die quicker!
I think the author is once again comparing apples to oranges. Perhaps it does not adversely effect our health to be slightly overweight but you cannot use that as evidence pointing to morbid obesity as healthy.
I'm going to veer off track just a little here and talk about cause of death. Many of the elderly die after breaking a hip. Did they die of a broken hip? Of course not! Suppose Mr Q dies of unresolved congestive heart failure, that's what Dr X will write on the certificate. If Dr X is feeling wordy and has lots of time he might write that the CHF was secondary to Mr Q's 387 lbs!
A persnickity statistics collector could then grab that as meat for this preposterous theory!
Yes, skinny people die too. Many actually waste away as they near death. Does this fact support shorter life spans for the underweight? I suppose it could if I was building my own ridiculous collection of nonsense.
I'd better stop rambling now ... grrrr ....