Essential amino acid requirements

Stuart Dunn dunns99 at
Tue Dec 14 06:06:51 EST 1999

Siemel B. Naran wrote:
> On Mon, 13 Dec 1999 10:33:23 -0600, River Mouse
> >Without all eight of the essential amino acids present, your body CANNOT do
> >anything with that protein except break it down to synthesize the
> >nonessential proteins and treat any surplus like fat.
> Well, the body may burn some muscle to make up for the difference (ie, for
> whatever amino acids are lacking).  Then the protein you eat is fully usable.
> But of course, we don't want this.
> >Whey | Soy | Egg | Rice | EAA
> >-----+-----|-----|------|----------
> > 6.8 | 4.3 | 4.5 |  4.2 | L-Isoleucine
> >10.9 | 7.2 | 6.8 |  8.6 | L-Leucine
> > 9.5 | 5.5 | 5.5 |  3.5 | L-Lysine
> > 2.5 | 1.2 | 2.7 |  2.4 | L-Methionine
> > 3.1 | 4.6 |  ?  |  5.2 | L-Phenylalanine
> > 8.3 | 3.3 | 3.6 |  3.6 | L-Threonine
> > 2.0 | 1.1 | 0.9 |  1.3 | L-Tryptophan
> > 6.4 | 4.4 | 5.1 |  4.7 | L-Valine
> >If methionine is the limiting factor, you'll need over twice as much soy
> >protein as you'd need whey protein to get the same usable EAA.
> >
> >Look at lysine, and you'll see that you need about three times as much rice
> >as you'd need whey.
> If you eat twice as much soy, you get twice as much of every amino acid.
> Which means too much protein, and therefore lots of work on your kidneys
> to get rid of the excess protein/nitrogen.
Thanks to the terrible job of health education that government run, tax
supported, "public" schools are doing, you have been misinformed. The
reason why they gave meat and dairy products their own food groups was
to help livestock farmers. Until you buy a calorie counter that lists
the amounts of amino acids in different foods, and until you go to
Walton Feeds website, you just won't know what you're talking about.
	It's not the ratios of different amino acids in your blood that matter.
You have enough of each amino acid in your blood to form the right
proteins for tissue growth. Eight of these must be supplied by the food
you eat, thirteen can be synthesized by your body if your food doesn't
provide enough of them, and nutritionists currently classify histidine,
the twenty-second amino acid, as only being essential for infants,
meaning that babies need to get it from breastmilk or infant formula,
but the rest of us don't have to worry about it. Now, in order to avoid
muscle atrophy (the first noticible symptom of a protein deficiency) you
need to replenish your amino acid pool on a regular basis. To do this,
all you have to do is eat at leaast two meals a day, maintain your body
weight, avoid eating abnormally large quantities of sugary fruit, and
restrict your consumption of junk food. By the way, the chart I am
talking about tells how many calories of any given food a 174 pound man
(that's about average in the US) would have to eat to get his RDA of all
eight amino acids. After looking at the chart, a person realizes that it
is not neccessary for even the strictest vegetarian to carefully combine
proteins. In fact, vegetarians and meat eaters alike are getting way too
much protein.
> >Some foods are heavier in sources than others. Since I want to rely largely
> >on soy sources for protein for the time being, I'm trying to find vegan
> >foods which are balanced in favor of lysine, methionine, threonine and
> >tryptophan to make up the difference.
According to the chart, if you weigh 174 pounds and you are an adult,
you would only need to eat 304 calories of soybeans to get enough of
each amino acid. If you eat fake meat made with soy protein, that number
would be even lower because most of the carbohydrates and fat would be
removed. I imagine you are smaller than 174 pounds, anyway.
 Peas and lentils are supposedly
> >heavier in these, so the combination of peas and soy protein may result in
> >something like whey's balance.
No, you don't need to balance amino acids. Read the American Dietetic
Association's position paper on vegetarianism.
> Grains are high in methionine, and maybe the others.  So wheat cereal and
> soy milk is probably a good choice.  
If you ate nothing but wheat and fit the description above, you would
need 1061 calories to get your amino acids.
I use tofu in my spaghetti (because
> it tastes good to me), and this might be balance too because tofu is soy
> and sphaghetti is grain.
Combining proteins is like combining vitamins to get a "complete B
Complex" or "complete tocopherol."
> >Mind you - that's -whey's- balance. I'm still looking for a source of
> >information on what ratios a body really needs.
Adults need 12mg of Isoleucine per kg of body weight, 16mg of Leucine
per kg, 12mg of Lysine per kg, 10mg per kg of Methionine and/or Cystine,
16mg per kg of Phenylalanine and or Tyrosine, 8mg per kg of Threonine,
3mg per kg of body weight of Tryptophan, and 14mg per kg of Valine. One
kg is about a pound.
 It may turn out that
> >tryptophan or one of the others isn't needed in as great a proportion.
> I think whole egg has the balance the body needs. 
I think you're refering to protein effeciency ratios, and yes, eggs do
have high protein effeciency ratios. Plant foods have low efficiency
ratios when eaten alone, but when you combine them with the other foods
eaten at the same meal it the ratio improves, and even if you only eat
one plant food per meal you would still be fine as long as you didn't
consistantly choose watermelon, apples, kiwis, etc.
 I looked hard on
> the internet for a profile but couldn't find one (all I get are links
> to products and info that I already know -- what the essential amino
> acids are and what each one supposedly does).  Anyway, as whey protein
> has a BV of over 100 on rats, I'd say it has the right ratios.
> --
> --------------
> siemel b naran
> --------------

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