I just re-read your original post and I think you named it right. - hopeless.
But it sounds like there has been some progress with the better foods that you have been sneaking in.
That could be your best hope to help with his comfort. At least it should help with his overall body condition.
Who knows maybe he'll get to feeling better and want to do better things for himself.
Even at that age people will get a glimmer of hope for their future if there is improvement in the way the body feels.
I think that that could be his biggest obstacle, - just lack of hope for the future.