Natural v. conventional

What is "natural"?

7Up is natural. High Fructose Corn Syrup is natural. One scientist and policy wonk says, "The ‘natural’ thing has always been such a morass,” via CD.

So, what about all those things at Whole Food Markup labelled "conventional"?

Don't let anyone see you buying this, or you'll forever be associated with bridge games, Norman Rockwell paintings, and missionary-style sex in the minivan parked in the cul-de-sac, via McSweeneys IT.