A public role for raising the alarm?  That's called special interest groups and scientists. Heck the tax funded CDC and NIH get in the act of warning and educating (of course that USDA food pyramid has been wrong)   Preventing a corporation....? We have a system called the free market, & no, we don't legally prohibit things that easily.  You may not like that food and beverages with sugar are sold, but you don't have a right to stop the sale or purchase by other people in a free society.  What's next, shut down all bakeries and restaurants?

Who thinks soda is "healthful"?  Unless one is completely illiterate, people know there are unhealthy foods & beverages.  You seem to think people consume naughty things only because they are stupid or ignorant.  Which federal institution was ever erected to stop people from making choices that might not be ideal?  

As for "integrity" in a "simpler era", you might want to read "The Jungle" or study up on the history of the union movement in the US