Re: Protein Counting

From: Daniel (daniel_r_at_email.it)
Date: 07/29/04 

Date: Thu, 29 Jul 2004 23:45:40 +0200

"Jan" <shantigiri@luukku.com> ha scritto nel messaggio
news:c0a6758c.0407241221.20ebafa2@posting.google.com...
> I guess you ask this question because you know that there are limiting
> amino acids in the vegetarian food. In your example that limiting
> amino acid would be lysine. However, I think that your question is
> theoretical and cannot be applied to real life as such. The reason is
> that there is an amino acid pool in the body where amino acids are
> stored at least for four hours, probably longer.

Actually lysine is stored for 15 days
Other amino acids are stored for days and only few are
stored for just one day
So you don't need to eat variety in the same day, you can also eat lysine
limiting foods Sunday and lysine rich foods Saturday
Also limiting is not the same as "deficient" or "devoid" even those foods
limiting in one essential amino acid are
adequate when you consume enough calories of them
So the limiting amino acid is adequate anyway

Here's the proof:

The following table shows the RDA for each essential aa in mg/kg bodyweight
(1), and per day for a
70 kg adult (2). Column (3) shows the essential aa content of pinto beans
in mg/100g of beans (100
g of beans contains 137 kcal total energy). If a person ate enough beans to
fulfill his daily
caloric needs (conservatively assumed to be 2000 kcal, he would get the
amount of each aa shown in
Column 4 ( = Column 3 divided by 137 times 2000). Finally, Column 5 gives
the percentage of the RDA
obtained from eating nothing but 2000 kcal of beans a day (Col. 4 divided by
Col. 2 x 100%).

                                (1) (2) (3) (4)
(5)
                               RDA RDA BEANS BEANS
Amino Acid mg/kg mg/70kg mg/100g mg/2000kcal %RDA
Isoleucine 10 700 363 5299
757%
Leucine 14 980 656 9577
977%
Lysine 12 840 564 8234
980%
Methionine 13 910 124 1810
199% <--
Phenylalanine 14 980 444 6482
661%
Threonine 7 490 346 5051
1031%
Tryptophan 3.5 245 97 1416
578%
Valine 10 700 430 6277
897%

What these results show is that eating nothing but beans would result in
obtaining a large excess of
every essential amino acid. In spite of the fact that beans are
_relatively_ low in methionine,
they are not _absolutely_ low in methione. Eating nothing but beans would
still provide 2 times the
RDA of methionine"

So, those foods low (not deficient) in one essential amino acid are two
times adequate for human
needs. So much for complementary protein, limiting amino acids and low
quality proteins

Daniel

Relevant Pages

  • Re: Protein counting
    ... It doesn't really work like you think, unless you eat nothing ... amino acid is tryptophan, at 37% of optimal. ... So much for being a "complete" protein. ... You can see the amino acid profiles of foods in the USDA ...
    (sci.med.nutrition)
  • The powers of Goji Berry!
    ... 19 amino acid including all 8 essential for life ... The richest source of carotenoids of all known foods ... Vitamin E (usually only in grains, seeds, and nuts ...
    (misc.health.alternative)