Please delete this if it is inappropriate!
That blogger used to post here, and in my unprofessional opinion showed clear signs of disordered eating. The fact that she went the other way and lost all control over her eating leads me to think her issues are much more complex than "she loosened up too much with diet because she though she could exercise them off."
She simply traded one ED in for another, which is not uncommon.

For the record, YES exercise for obese people is more dangerous (I'm a personal trainer with a M.S. in exercise science)- BUT there is always a way to reduce injury risk and work out. And yes, Crossfit does MODIFY level of difficulty to each participant. There is nothing inherently wrong with CF- there are simply bad COACHES.
And your obese client will actually often EXCEL at things like a rowing machine because they have so much muscle under all the fat from simply carrying that weight burden around in their normal lives. on a rower, you are taking away the burden of carrying that weight, and boom! when you put the person next to a skinny minny, the obese client often will "win" the race! it's pretty cool to see them light up, when they realize "i CAN do this."