No one has said otherwise, all poison always depends on the dose.
The problem is that humans are not very adept at controlling doses of alcohol, drugs or junk food.
That is why it will depend on each one how they can handle their vices and whims. For many it is all or nothing, so absolute abstention is their only way.
And as the issue was raised in this thread, it was something like getting drunk or eat tons of shit food every day for 3 weeks? I don't see how that has anything to do with physical or even mental health. And for those not concerned about health, I also do not see what benefits it could bring at the level of muscular look.