I finally read quickly through the Cordain vs. Campbell debate. Cordain
didn't really need to do anything, because Campbell asserted such
contradictory arguments that he essentially debated himself.

Campbell vs. Campbell
From: The Protein Debate (Loren Cordain, PhD vs. T. Colin Campbell, PhD)
http://www.performancemenu.com/resources/proteinDebate.php

Campbell1: <<Our dietary evolutionary history, while interesting, absolutely
does not yield critical clues for optimal nutritional practices. Human
evolution required that our ancestors make dietary choices that maximized
gene proliferation. And that is absolutely the ONLY thing that such
practices yielded....>>

Campbell2: <<[T]he "evolutionary history of anthropoid primates" going back
25 million years "shaped their nutrient requirements and digestive
physiology well before they were humans or protohumans"....>>

My take: Huh? The evolutionary history of humans over the last 2.5 million
years provides no clues for optimal human nutritional practices, but the
evolutionary history of non-human anthropod primates going back 25 million
years does? Is evolutionary history relevant or not, and why would non-human
primate evolutionary history be more relevant than human evolutionary
history?

Campbell1: <<Increasing dietary protein above this 10% level generally means
adding or substituting animal-based foods for plant-based foods but doing so
invites a plethora of adverse health effects. To be very clear, I believe
that total dietary protein should be 10% of calories, with virtually all of
it being in the form of plant-based proteins.>>

Campbell2: <<[A]bout 90% of vegetarians still consume dairy products, among
other animal based foods, thus minimizing the difference in nutritional
composition from non-vegetarian diets. It is somewhat surprising to me that
we even observed statistically significant decreases in disease rates with
such small differences in nutrient composition.>>

My take: So which is it, do we need to make sure that we don't include any
animal-based proteins in our diet and that plant-based proteins only account
for 10% of daily calories because vegetarians are so much healthier than
omnivores and more than 10% protein has such terrible health effects, or do
most people who call themselves vegetarians actually consume dairy products
and other animal based foods and the differences between vegetarian and
omnivorous diets is actually quite small? How do we know that we need to
eliminate all animal foods from our diets if such a small percentage of
"vegetarians" actually do this?