Because poor health choices of individuals increases the healthcare costs on everyone else.

That's irrelevant when weighed against the fundamental freedom of the individual. Healthcare systems can change to accommodate fundamental freedom. Individuals shouldn't give up fundamental freedom to accommodate an artificial system that can be changed.

I say not taxing it goes against freedom when future problems are not paid by the responsible person.

Yes, please defend my freedom to have my health ruined by food companies that literally bring in food scientists for the express purpose of making you crave their food while finding it unsatiating so you keep eating it. While you're at it, could you defend their freedom to buy up all the small farms so I have no choice but to eat what they sell?