On Fri, 17 Sep 1999, Amadeus Schmidt wrote:

> Todd Moody wrote:
> >But if you stick to the 35g maximum per meal, it should be
> >possible to consume 5 such meals in a 16-hour day.
>
> What you describe are the insulin/glucagon level timings,
> the body trying to keep blood sugar at an equal level.
> But that concerns obviously only the response to the part of
> protein  which is actually converted to sugar.

And that portion, if any, which is converted to fat.

> Still it isn't clear how long it takes until the
> useable amino acids from the first 35g of one meal are used up.
> Hm probably there are other hormonal signals that could be measured
> to decide this. Protein synthesis signals for example.

It seems to me that we get a clue from the fact that values
return to baseline after 4 hours and we get similar hormonal
results at the next meal.  If there were not enough "room" in the
blood 4 hours later for the amino acids from 35g more protein, we
would expect a greater insulin surge because more of the protein
would have to be stored as fat.  As far as I know, this doesn't
happen.

> In annother message you posted that protein synthesis
> was triggered by glucagon presence (absence of dietary glucose).
> Could you clarify your source, please?

I don't know; that doesn't sound right.  If I said that I think I
was wrong.  Glucagon is important because, among other things, it
serves as a counterbalance to insulin at the cellular level.
Glucagon upregulates the production of the D6D enzyme that is
needed to convert ALA into DHA and EPA, for example; insulin
inhibits it.

> Yes, the amount circulating in the blood is, what i counted as
> the (short term) "storage".
> There is a long term "storage" too of course, the complete proteins
> of the body for example from muscles, intestine cells.
> I haven't heard yet, that the body would build up muscle cells
> just to store the proteins.
> Though that would be the dream for body builders :-))

This implies that blood volume ought to make a substantial
difference to how much protein one can assimilate per day.  Body
builders have lots of muscle and lots of blood vessels to keep it
fed.  Moreover, they systematically damage their muscle tissue
repeatedly by subjecting it to the stresses of weight lifting.
The result ought to be a higher than normal ability to accept
amino acids into the blood and a higher than normal demand for
them.  This may explain why body builders seem to be able to eat
rather large amounts of protein without gaining body fat.

Todd Moody
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