I feel like the odd man out, but I'd take the disability.
Maybe it's how I read the question - I read it to mean that I would be obese permanently or have a permanent disability.
My top weight was 340, if my choice is to 340 for the rest of my life or to be deaf for the rest of my life, I'll take deafness. Diabetes, well, they didn't say uncontrolled diabetes, I'm assuming I can still live a full life with my insulin shots, so I'll take diabetes. Heart disease? I'll take it and get lots of exercise & watch my cholesterol. An amputated leg? Protheses are great these days, I can still do my 5 & 10k races with a prosthetic leg. Bad acne? Please, I'll wear more makeup. Blindness is a little tougher, I might have to take my former weight over blindness, the lack of independence from being blind, just not being able to drive where I want to go, might be enough for me to prefer weighing 340 lbs everyday.
If the question wasn't permanent obesity, just a question of waking up tomorrow at 340lbs (which I could try to re-lose) or one of the disabilities, my answers might change, but frankly, I don't think that's how the question was intended. I think it was intended as a permanent obesity vs a permanent disability. And since the question was asked of people large enough to need gastric bypass surgery, I think that presupposes obesity of at least 100 lbs over your current or planned maintenance weight, as that's the approximate minimum of obesity needed before surgery is considered.
I'd be curious if anyone here would change their answer if the question was re-worded to be a permanent obesity of 100 lbs overweight versus those disabilities.