The above link is to a story by a blogger about some parents that were being generally rude and annoying. A lot of it is dietary specifics but if you can imagine the attitude behind it... wow.
Why I'm talking about this possibly made-up story is because I know SO MANY PEOPLE exactly like this! Not the rudeness (uncalled for) or the dietary specifics (fine) but the reasoning behind the dietary specifics- a lot of poorly researched bs. "O I heard from a friend" junk.
There's very few things that would qualify as an excuse these days for not doing your research.