To describe such a person as "vulnerable" is a little silly. Their vulnerability is something they created themselves.
If you want people to stop eating fast food and watching TV all day, give them something more to live for than their next junk food hit instead of making their continued survival even more uncertain.
I think they merely have different utility functions than me, and assign a lower value to health, but a higher value to leisure. And I'd argue they have the right to continue eating chips and watching TV - they just don't have the right to force other people to pay for their choices.
But lets take your theory of mental incompetence seriously - in that case, isn't the solution some sort of institutionalization? I.e., assign some bureaucrat to make good choices for them, rather than merely forcing responsible adults to pay for their irrational bad choices?
It's probably worth mentioning the philosophy that drives my opinions on these issues. I want to minimize individual and total human suffering while maximizing individual and total human potential. In other words, I believe that every human being should have the right not to suffer, along with the opportunity to make their best contribution to the progress of humanity. Being poor and trapped by the mental stresses of staying alive leads to suffering, fast food temporarily alleviates that suffering, and increasing the cost of health insurance will exacerbate that suffering. I still care even if it's someone else suffering while I enjoy the money I might save each month by not paying for their lifestyle.
You seem to want to have it both ways. Either the poor are adults capable of making their own choices, or they aren't.
If they are mentally competent, they have the right not to "suffer" ("suffering" isn't the word I'd normally use to describe a life of leisure). They just choose not to exercise it.
Hardly. I certainly wouldn't hold a person being tortured responsible for their actions, but I also wouldn't permit them to make their own decisions.
My position is that the right to make a choice and the responsibility for that choice go hand in hand. Either the poor are allowed to make choices and suffer the consequences, or they aren't. If you'd like shades of grey, perhaps they could jointly make decisions with a guardian, and the guardian is partially responsible for those choices.