What is the maximum number of grams of protien that an individual can
efficiently absorb from one meal? I do not want RDA information. I
want information from scientific nutritional studies.

Hello pkk-ga,
    In short, ~1% of the protein in your meal will not be absorbed and
pass through your system into your feces.  If you have a 100g meal,
about 1 gram will resist absorption, if you eat 10 grams, .1 gram will
escape the absorption process, it is a relative amount depending on
the amount of protein in your meal rather than an absolute number. 
Assuming that you are otherwise healthy and have no digestion
problems.
    The way protein absorption works is partially based on the
efficiency of your body's ability to properly digest (break down)
protein into it's amino acid subunits.  This happens to a small degree
in the stomach but more so in the duodenum (the first of the three
compartments in the small intestine) the major absorption site of
protein is the jejunum (the second part of the small intestines).  The
intestine normally will not absorb anything larger than a tri-peptide
(three amino acids linked together).  There are 20 amino acids, and
their absorption happens through one of four types of transporters
responsible for absorbing specific types of amino acids or
tri-peptides.  There is a specific transporter for neutral, acidic,
and basic amino acids, as well as a transporter for proline and
hydroxyproline.  Sometimes the amino acids and tripeptides will
compete for absorption at these transport sites, hence the 1% that
does not get absorbed.  The process by which food moves through the
intestine is so slow that by the time the food has moved though the
jejunum all but about one percent is absorbed.
  As I said, the final absorption depends on the initial ability to
digest long protein chains into small absorbable amino acids, di- and
tri-peptides.  Enzymes the body makes for protein digestion depend on
the kinds of proteins you eat.  Since your body adapts your enzymes to
the foods you eat, this explains why long time vegetarians and vegans
become ill when they eat meat proteins.  They cannot digest it anymore
because they lack the enzymes, and in that case they would have an
altered MEAT digestion rate and very low absorption.  It is a
reversible process if they slowly make meat proteins a part of their
diet again.
    So again, you absorb ~99% of the protein you eat unless you have
some kind of illness altering your digestion or absorption or have not
eaten meat in a few years.
  
I hope this answers your question, please tell me if you need
clarification.


    melly-ga


Mahan Kathleen, Escott-Stump Sylvia.Food Nutrition and Diet
Therapy.W.B. Saunders Company:Philidelphia,2000

Good book about nutrition and biochemistry as it applies to the human
body