Self-Sufficiency Percentage

Matt Mullenix raised an interesting figure in his comment to my last post, "Endangered Agribusiness."

"Just think how large a cow Big Ag would have if the average American provided even as little as 10% his food needs through gardening and hunting?"

Have any of you ever put pencil to paper to calculate how big your garden would have to be or how much fish and game you'd have to put away for you and your family to achieve a certain level of self-sufficiency?

I like Matt's figure of 10 percent self-sufficient. It seems reasonable, though I'm afraid I'd be shocked at just how much gardening, hunting, and fishing I would have to do to achieve it - even for just Jane and me.

Any thoughts? Suggestions for making such a calculation?