question on incomplete proteins

[Herculean]

im sure most of you already know that the only foods with the 8 essential amino acids needed in proteins are only found in meat , dairy / poultry

if you are eating a meal which does not contain either you have to mix them up to get all the amino acids ..

example , bread + peanut butter , beans + rice , pasta + cheese


what i was wanting to know though , is how do the ratios work ? say i eat 10g of a copmlete protein with a food that has 30 grams of incomplete protein .. how would the amino acids with the 10g be enough to absorb the 30g in the incomplete protein?

will the body absorb it all ? or will it absorb only a certain ammount?

if i ate 200 g of pasta then drank a small glass of milk later on , would the body absorb all the protein in the pasta???

is there some kind of ratio of proteins that needs to be taken into consideration?

not to sure how to word this question , im sure someone there knows what i am talking about.

 

[Grady]

I don't know the answer, but I this also occurred to me, and I felt it was logical to deduce that eating all 8 essential amino acids but in unequal percentages, any "leftover" amino acids that doesn't match up with the other parts to make it complete probably get converted to glucose-chains or lipids for energy storage purposes. However, you inspired me to do a couple minutes of googling (isn't the Internet great!!?).

Found the following on the web, so you could likely derive ratios from this...

"Essential amino acids for adults and their RDA (Recommended Dietary Allowance 1989) are: isoleucine (10 milligrams); leucine (14 milligrams); lysine (12 milligrams); methionine (13 milligrams); phenylalanine (14 milligrams); threonine (7 milligrams); tryptophan (3.5 milligrams); valine (10 milligrams). Infants also need histidine (28 milligrams). These amounts are per kilogram of body weight per day."

Also, I found this, looks like a online info and quix for bio students... http://animalscience.tamu.edu/nutr/202s/LectureOutlines/protein2.html

" IV. Overview of Protein Synthesis and Metabolism

A. Protein Synthesis
1. DNA encodes the information for protein sequences.

2. DNA serves as a template for messenger RNA (mRNA) synthesis.

3. mRNA codes for 20 amino acids.

B. Metabolism of excess amino acids
1. A.A. in excess of requirements for protein synthesis (or other N compounds) cannot be stored.

2. The nitrogen is removed (deaminated) from amino acids that are in excess.

3. What happens to this nitrogen?

4. There is 1g of N per 6.25 g protein.
5. What is the remaining carbon chain is used for?

C. Protein synthesis requires all necessary amino acids at the time of synthesis.

1. What are the consequences if one essential A.A. is not present in adequate concentrations?

2. Nitrogen and non-essential amino acids.

D. Protein Turnover and Nitrogen Balance
1. Proteins in our body are continually being broken down and re-synthesized (turnover).
2. Nitrogen balance: nitrogen intake - nitrogen output (loss)
3. Describe situations of negative, zero, and positive nitrogen balance.
4. Why are adequate calories (especially carbohydrate) protein sparing?

 

[Herculean]

I don't know the answer, but I this also occurred to me, and I felt it was logical to deduce that eating all 8 essential amino acids but in unequal percentages, any "leftover" amino acids that doesn't match up with the other parts to make it complete probably get converted to glucose-chains or lipids for energy storage purposes.

yeah but this would mean that you are not getting the protein out of the remaining A.A
so when you eat pasta with a cheese sauce , you are only getting protein from the cheese sauce which might be 10 grams ... what is the point of even putting amount of protein on the pasta packet when the protein is not even used(as protein) . and if it is used , it can only be used if another source of protein that has the rest of the amino acids and has the exact same amount of protein as in the pasta??


and if this is the case then why is it never explained on any webpage , they just say to combine proteins , example rice + legumes ... so your body does not get the 8 essential acids from legumes it might get 4 but the rice has the the other 4 , anyway ... the protein in the legumes is around 30 grams in total but the protein in the rice is only around 8 grams in total ... so either you are only getting 8 grams of protein(that is used by the body) or the 30 grams somehow combine with the 8g rams to make a total of 38 grams.

bah

have also read that u do not even need to combine proteins in a meal , that you could eat a plate of beans then a few hours later eat some steak and protein from beans would still be used or something... *shrug*

 

[thecas]

Have you seen it from another perspective? Like if it is 1:1 of certain 2 AAs. You eat 2:1. So AA number 1 will have extras. The extras will b used to build extra muscle or brain or whatever, instead of broken down. You are implying that everything needs 8 AAs, But a more likely answer is perhaps some organs need more of some particular AA, others others.

 

[Grady]

Well, you could do some research on the web. Or, make the ratios from the RDA info I posted, because the AAs you need do not seem to be 1:1... ie. equal parts for each of the 8 essential.

Or, just eat more fish and chicken, drink more milk, and know you are getting the right combo!

(I agree about the pasta example, pasta and cheese probably won't net you more complete protein than whats in the cheese unless you throw some beans in there.)

Manufacturers can list the protein in grams for incomplete protein products like pasta and rice because it is true -- there is really 'x' grams of protein in there, even if your body can't utilize it much if you don't supply the missing AAs with something else. Maybe one day the nutritional informations will list the number of AAs rather than lump the entire thing under 'Protein.' Also -- note that there are a lot of protein forms, it is only the AAs that your body cannot synthesize.

 

[Herculean]

coming back to the question , i posted mainly about eating complete proteins with incomplete proteins ... it would be safe to say that if i ate 200 grams of pasta which contains 16 grams of protein with 50 grams of cheese , i would only get the true protein in the cheese ..... with the pasta i would still AA from the protein inside , possibly get an extra boost of A and B amino acids the non essential amino acids would be used for something esle or kept for later use possibly . since the body can synthesise the other 13 AA's needed for development without eating the specific foods.


however , if i were to eat the pasta with beans then i would get a complete protein per say but the amount of protein would depend on the ratio of the 8 AA's

and well i guess well that was my question , what classifies as complete protein? , what is the ratio? is there a ratio?

obviously it is not euqal amounts of isoleucine ,lleucine , lysine , methionine , phenylalanine , threonine, tryptophan and valine


though maybe it is close to equal amounts .. or does it all just sit in a "storage pool" all the AA's mixed up and waiting to be used so whatever you eat just kind of breaks down and enters the "pool" which in turn looks to synthesise every x amount of time or something..

eitherway , it would be interesting to find out , and yes i have been "googling" now and then for all the times u mentioned this. though this question is a bit specific and was not quite sure on how to word the question ....


again going back to examples i used before ..lets say that the 8 essential amino acids are broken up into A B C D , with 2 AA's in each ... now if i eat beans which has 20 grams of protein from A+B and eat the rice which has 10 grams from C+D and these 4 make up the total amount needed . then i would assume from what i have read that the AA ratio would or should be enough to make 40 grams in total of complete protein , with a slighty un even amount of the 8 AA's.

or would it ? does there have to be a certain ratio for protein to be considered a complete?






found this interesting article on AA's


I've heard that in order to reap the benefits of complementary proteins, I need to eat them at the same meal. Is this true?

No, it used to be believed that for two incomplete plant proteins to complement each other and give the body all the essential amino acids, they had to be eaten at the same meal. Being a vegetarian seemed complicated, even risky. Now we know that this is not only nutritionally incorrect, it is an insult to the wisdom of the body. When you eat a protein, your body disassembles it into amino acids and then reassembles these amino acids into the types of proteins needed by different cells. New studies show that incomplete proteins (plant proteins) eaten as much as 24 hours apart, combine in the body to provide all the essential amino acids. So, you could eat grains at breakfast and legumes at dinner, and the body will still be able to mix them all together and make what it needs. As long as you eat a variety of protein foods from a variety of sources, you don't have to constantly worry whether they are "complete" or "incomplete" proteins. Your body will do the thinking for you.


just eating good and getting complete proteins in sometime during the day is fine enough ,but i was interested in complete / incomplete proteins and mixing , no site ever mentions anything about how much or what to mix , it just says that "mixing" is fine .. for those of us that exercise , ok so maybe we do not count every gram we take in but i am sure we have a rough guess from day to day , it seemed that these sites did not mention much more than the types of food to mix.

 

[Grady]

I've heard that in order to reap the benefits of complementary proteins, I need to eat them at the same meal. Is this true?

No, it used to be believed that for two incomplete plant proteins to complement each other and give the body all the essential amino acids, they had to be eaten at the same meal. Being a vegetarian seemed complicated, even risky. Now we know that this is not only nutritionally incorrect, it is an insult to the wisdom of the body. When you eat a protein, your body disassembles it into amino acids and then reassembles these amino acids into the types of proteins needed by different cells. New studies show that incomplete proteins (plant proteins) eaten as much as 24 hours apart, combine in the body to provide all the essential amino acids. So, you could eat grains at breakfast and legumes at dinner, and the body will still be able to mix them all together and make what it needs. As long as you eat a variety of protein foods from a variety of sources, you don't have to constantly worry whether they are "complete" or "incomplete" proteins. Your body will do the thinking for you.7

That is an interesting exerpt, and to be honest that probably makes sense from an evolutionary standpoint (that the body MUST have some storage ability for incomplete EAAs). I would be willing to bet that it is far less efficient than eat complete EAAs in a meal. Since the body can utilize protein as an energy source, if you have incomplete EAAs floating around in your blood, some of them probably get converted or metabolized.

In short: if I were a vegetarian, I would definately eat complete protien combos in each meal, even if the body has a storage mechanism.

 

[talking.dingo]

There is a sticky ( I think) on the conditioning forum discussing NPU and bio-availability of certain foods and the protein therein. This idea is promulgated by the FDA. I am not knowledgable enough at this technical level. But I think the concept of bio-availability and nitrogen assimilation has the answer to your question.

Good luck. Keep searching.