On Wed, 16 Sep 1998, Amadeus Schmidt wrote:

> I may quote Loren Cordaine from Paleodiet where I found:
> ..."
> Additionally, bone mass is also dependent upon the relative
> acid/alkaline dietary load (2,3).   Acid generated by the diet is
> excreted in the urine and can cause calciuresis.   Meat and fish have a
> high potential renal acid load (PRAL) whereas fruits and vegetables have
> a negative PRAL, meaning they reduce acid excretion.   The human kidney
> cannot excrete urine with a pH lower than 5; consequently  the acids
> (mainly phosphate and sulfate) of acid producing foods such as meats,
> fish and some cereals must be buffered partially by calcium  which is
> ultimately derived from the skeleton (2,3).
> "... end of quote
>
> Whole thing is at:
>
> http://maelstrom.stjohns.edu/CGI/wa.exe?A2=ind9806&L=paleodiet&F=&S=&P=266
>
> IMO quite a reason *not* to consume over protein or protein as
> a caloric source.

We should define "excess protein" as "more protein than the body
can use in ways other than as fuel."  Given that definition, what
counts as excess protein will depend, among other things, on
available non-protein calories.  This implies that a high-protein
low-calorie diet is a bad idea as a long-term way of eating.
It's probably okay as a short-term strategy for weight loss.
From what I have read, the amount of protein that the body uses
for non-fuel purposes is *not fixed*.  That is, it can utilize a
little or a lot.  I have read that the ceiling is about 300g/day.
(That also from Cordain, I think)

Weight loss always involves *some* protein being burned as fuel,
I think, including both dietary and muscle protein.  A ketogenic
diet appears to minimize this but I don't believe it eliminates
it altogether.

Todd Moody
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