Hmmm? I'd heard of this idea back in the 80's, touted by some alternative lifestyle folks, but, never gave it much thought and it seemed to disappear. Then a commenter here, reminded me of this notion. I'm not certain what I think about it, but, it seems debatable.
When you read the Wolfe Clinic suggested list of foods... most of the "alkaline foods" are foods that are good for you and you should just eat. Most of the "acid foods" are foods that can be good for you but that you should eat in moderation. That is if you are eating a zone plan, you are approximating the "alkaline/acid" recommendations, anyway. But apparently the goodness is for a different reason -- just plain good nutrition, perhaps?