But jokes aside, the answer actually did surprise me. It's so easy to forget that there was a time when processed food was an oddity. Now we often can't tell the difference.
I forget what year it was ('72 or '74 I think) but over half of the currently used food additives were all cleared for human consumption at about the same time in the mid 70s, and we're probably going to start seeing the the unpredicted long term side effects really kick in to full gear in the next decade or so.