Hi Joseph, 
Thanks for these several insights. 

I'll be sure to credit you as a source too.

I knew about how calories were measured, but not ph. I haven't been able to
find much on it yet either. I'll keep looking though. 

Again, thanks for the input. 

Best Wishes, 
Ron

-----Original Message-----
From: Paleolithic Eating Support List [mailto:[log in to unmask]]
On Behalf Of Joseph Berne
Sent: Sunday, September 13, 2009 4:27 AM
To: [log in to unmask]
Subject: Re: Great blog post about saturated fats

Whether a food is considered an acid-contributor or an alkaline-contributor
to your diet is not based (no pun intended) on whether the food is acidic or
basic (for example, lemons are base-producing but are definitely acidic when
consumed).  The foods that are acid promoting are foods that contribute
hydrogen ions to the system when they are metabolized, not in their
pre-digested form.  I am not having an easy time finding references that
really explain the chemistry behind this, and my biochem background is sadly
far in the past.
One problem I'm having is that foods are described as acid promoting or base
promoting based on their ash.  I've actually seen websites where this is
taken to be a metaphor, but I'm pretty sure that someone just takes the food
and burns it, then tests the pH of the ash (which is similar to how the
caloric content of food is measured).  The problem for me is that burning
foods is not the same as what your body does to get energy from them - an
obvious example is fiber.  I mean, you can burn fiber in a bomb calorimeter,
but your body can't get energy out of the stuff, which is why the calorie
content on high fiber processed foods is so off (and, I suspect, part of the
reason why high fiber foods seem to promote weight loss in some studies -
 you don't get as much usable energy out of the high fiber foods because
your body can't metabolize it).

I suspect you guys are onto something regarding the fat content of the food.
 I'd feel better if I really understood all the chemical reactions involved
in the metabolism of various micronutrients, but when we studied this we
always ignored the hydrogen ions - you study chemistry in an aqueous
environment and you tend to ignore any H+ ions that get produced with a wave
of the hand and an occasional "don't worry, the body will buffer this
away..."