Okay now, I'm confused.
I will admit I've never been familiar with someone grossly obese who lost a major limb. so I may be in outer space here.
Wouldn't someone who's undergone major bodily trauma (removal of a limb) and who's probably got a host of other ailments (heart, kidneys, stomach, whatnot), tend to lose weight involuntarily, instead of keeping it or adding on to it?