On Mon, 19 Aug 2002, Craig Smith wrote:

> Could you say more about this "protein ceiling"?  What happens if
> one goes beyond the 300g/day?  Is it that the excess is turned to
> fat, or that it aggravates diabetes, or what?

This number is an average, and it would vary from person to
person somewhat.  As I understand it, the liver must produce urea
to metabolize the protein, and the limiting factor is how much
urea the liver can produce in a day.  If one eats more protein
than this, there is a buildup of proteins metabolites, leading to
toxicity.

The "rabbit starvation" phenomenon described by Stefansson is the
sickness that results from this, apparently.  If you eat lean
protein and nothing else, you could consume about 300g/day
safely, which is about 1200 kcal.  If you ate more, you'd start
to get sick.  Why would you eat more?  Because at 1200 kcal/day,
most people --men, at least-- would be very hungry.

This is what is remarkable about the coastal aborigines.  They
seem to have adjusted to this caloric intake, at 80% protein
(below the ceiling), and 15-20% fat.  This could be because they
have learned that, given their food sources, they can't eat much
more and feel well.  Or it could be that so much protein is so
satiating that they simply don't want much more food.

I have been experimenting with a similar sort of diet, and I do
find it very satiating.  It takes a while to digest that much
protein, and while that is happening, the desire for food goes
away.  It certainly has worked to get weight loss going again.

Todd Moody
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