Wouldn't there be major issues with post facto laws in the case of food like many other weasel worded usages of "holding accountable"? I swear, the tobbaco laws

Wouldn't there be major issues with post facto laws in the case of food like many other weasel worded usages of "holding accountable"? I swear, the tobbaco lawsuits have turned lawyers into junkies for grand lawsuits which has them looking to find the next big tobbaco whether the target deserves it or not. Unlike tobbaco there is nuance about consumption as good or bad on a per person level, and there was never any obligation nor capability to police the diet of their customers. It isn't like cigarettes where ideal consumption is zero.