Humans have apparently been using fire for at least 300,000 years, possibly
more than 500,000 years.  I find it inconceivable that there would not be
some adaptation to cooked foods in that time period.  Whole species of
animals have evolved and gone extinct in less time than that.

Furthermore, peoples' lifespans went UP, not down, when they started
cooking.  So much for the instinctotherapy philosophy.

However, I find it just as inconveivable that there would be much
adaptation to any food which requires lengthy or complex cooking
procedures.  The cooking your average cro magnon or neanderthal would have
done would largely have consisted of what you could jam onto a stick and
hold over a fire, or cook with hot rocks, or wrap in an animal's stomach
and roast over a fire.  Furthermore, there would be a sharp limit on the
amount of things like beats, beans,or potatoes that they could have gotten
their hands on anyway, since such things cannot usually be found in mass
quantities in the wild, and putting together enough grain to make a meal
would be a ridiclous amount of work for any hunter-gatherer.

The "naked with a sharp stick" philosophy as I understand it isn't supposed
to be an absolute, inviolable definition.  It's a rule of thumb, a handy
guideline that works most of the time.  There will certainly be odd
exceptions there.  For example, macadamia nuts are probably all right to
eat as they're not substantially different from other nuts.  And yet it
would be nearly impossible for someone who was naked and armed only with a
sharp stick to eat a macadamia nut, because the shells are so damned tough
you probably couldn't crack one without a couple of really big rocks, or
better yet a sledgehammer.  Also I don't think any rational person would
suggest that a food killed with a spearthrower rather than just a sharp
stick is somehow an unnatural food.

It seems to me that there should be a point where common sense dictates.
I've heard people criticize "Neander Thin" since we are apparently not
descended from Neanderthals.  Which shows what can happen when you get too
literal-minded or too locked into one way of thinking.  If I really ate
unlimited amounts of fruit I would get likely sick and gain weight on
NeanderThin.  On the other end of the stick, there are good paleolithic
(and practical) reasons to suggest that eating meat separate from fruits
and vegetables may be a more natural and healthy way to eat.

Neander Thin itself represents a big compromise on paleolithic nutrition
standards, becuase if you were going to be a true paleolithic dieter you'd
never set foot in a supermarket or refrigerate anything.  There is a point
on all this where common sense should dictate.