That is so wild. I really feel for you. I may be facing the same thing. I'm 5 feet 3 and weigh 190 and to me it's been a huge issue for my whole life. But that may not be enough for the insurance companies.
How does one calculate the body fat ratio?
Well, I say do it. Enjoy the crappy food if you can. It's wierd, as easy as it is to gain weight, when one HAS to do it, it is difficult. Especially when one basically prefers healthy food. I bet some Protein shakes might buff you up a bit.
Good luck.