You are submitting to force.
We don't live in a vaccum.
Like others have said - personal responsibility needs to play a greater role.
I agree. But how? taxes are one option, but are there others. This mythical "personal responsibility" seems to be code for "who cares, just let them die". Which might be fine for many judging by the responses, but the thing is I will pay more tax and society will make a loss if that happens (less workers, money wasted on disease expenses etc).
I can just imagine fat/unhealthy people not accepting any responsibility for their actions on the basis that they paid the tax, and as such are allowed to be as unhealthy as they want and shuffle most of the costs onto everyone else.
There is no law against being fat (no "state force" here!) or eating whatever you want. This is where "personal responsibility" has got us to.
If you want a "Fat Tax" then base it on Body Mass Index.
Eating too many carrots makes your skin orange. That's not good. Should we tax carrots?
This is even worse than a tax. Why is this even being suggested? It is humiliating and unethical. Excessive carrot consumption and harm that results hardly has the impact on the budget that obesity does.