Talk:Protein quality

}} }}

Untitled
What about fish and other sources of protein? — Preceding unsigned comment added by 181.37.60.50 (talk) 13:02, 20 July 2019 (UTC)

Rewriting of the lead
Margalob, I have to slightly disagree with you rewriting the lead here, because protein quality isn't only determined by digestibility and EAA minimum requirements. It's true that PDCAAS and DIAAS focus mainly on those two aspects, but the other and older methods focus on other aspects. And for example, Biological Value and Nitrogen Balance (I haven't included it yet) are the methods (especially BV) that are still promoted by various bodybuilding supplement manufacturers. HempFan (talk) 15:43, 11 May 2016 (UTC)

Protein ranking section
How is the value in the Complete Protein column determined? For example, Soy has a PDCAAS of 0.91, and Beef is 0.92, and they are both listed as complete proteins, while Mycoprotein is listed as having a PDCAAS of 0.996, yet it is listed as not a complete protein. Why is that? Also, how are you defining Complete Protein? It doesn't seem to match up with the Complete Protein article.--SaletteAndrews (talk) 15:44, 15 January 2017 (UTC)
 * Some IP address editor changed soy, beef and mycoprotein to complete proteins, I've fixed it now by reverting those edits. HempFan (talk) 17:48, 24 October 2017 (UTC)
 * But why did you revert the soy edit? According to Complete_protein, Soy_protein, and many Google sources, soy is complete. --Jason C.K. (talk) 20:26, 19 November 2018 (UTC)

Amino acid profile section
Hi, I added a new section, please have a look at it and correct me where I did something wrong with the formatting and such. Also, USDA.gov while a reliable source, isn't the most accurate information on amino acid profile from what I've noticed, because I don't know how they've calculated it, but the numbers aren't always adding up properly. HempFan (talk) 15:11, 12 May 2016 (UTC)


 * Hi, I think there may be some problems with the figures on this section. Looking at the USDA pages that are linked in the reference they are quoting figures per Kg for amino acids not per 100g which is in the first column. 100g of egg white does not contain 54g of essential amino acids. The quantity of histadine in 100g of egg white is 0.29 g. I think the required per 100g of protein needs to be explained more, usually protein requirements are given in relation to total body weight, i.e. Xg per Kg needed to maintain that body weight. Let me know if I've missed something (Chrisdean (talk) 17:44, 22 April 2017 (UTC))


 * Yes, well the issue is that the amino acid profile on USDA pages, is often taken from separate analyses, so for example, if you look up 100 g hemp seeds, you'll notice that it lists protein at 31.56 g, yet if you count the amino acids, you'll get 34.354 g of protein (which is normal for hemp seed protein variation, usually being somewhere between 30-37 g of protein depending on the seed variety), and this is not just a mismatch with USDA's hemp seed profile, but also most other nutritional values (whey, soybeans and so on). I was aware of this when I created this article, but I just went with 100 g of protein instead of 100 g amino acids, because it was faster to do it that way (to get 100 g amino acids, I would have had to calculate all amino acids first to get the accurate 100 g amino acids values). Like I said, this is because for many food analyses, USDA does separate analyses for total protein content and total amino acid contents (this is normal; food analyses usually consists of multiple analyses, depending on what nutritent(s) they're analyzing for). I'll correct the scores later, as it requires a lot of meticulous work. HempFan (talk) 18:01, 24 October 2017 (UTC)

Humbly asking permission to edit
I made some fairly simple changes (even if it did take more than a half hour of work), and they've been reverted without giving any reason. I was just told to go discuss it here. I find this very unfriendly. I'm not saying that putting time into editing means that the edits have an automatic right to stand, but I do think it should be common courtesy to explain a revert after someone puts in more than 30 minutes of work.

Below are my reverted edits. I explained each in the edit summaries, but I'll explain them further here:


 * Add an example with numbers for having to eat more soy to get the same levels of the limiting amino
 * Remove some extra blank spaces and put each table header on a new line so they're easier to find
 * Remove the spaces and the letter "g" so that the table rows don't have to wrap, doubling the length of the table on some screens
 * Remove a claim that's been unsourced for over a year, and a column which has values that are contradicted by the linked article

Wikipedia lives on contributors. Reverting is a very aggressive move and does the opposite of what we need for community-building.

So firstly, I'd like to reinstate these edits. Anyone have a problem with the above edits?

Secondly, and more importantly, can we stop the aggressiveness and insta-reverting? It's really offputting. Great floors (talk) 09:14, 2 February 2018 (UTC)
 * Just a comment,, this edit, as elsewhere in the article, focuses on a single food about whether it's a "complete protein source", which to any food scientist or dietitian is unrealistic and moot in context of a multi-food, multi-source protein diet. Your other edits were fine by me. --Zefr (talk) 16:56, 7 February 2018 (UTC)
 * Indeed, I wanted to write what you just said (about the problem being hard to create in the real world), but I figured that was too radical and would be reverted, so I went for a more conservative edit about how the problem, if created, only requires eating slightly more of whatever food is being eaten. Great floors (talk) 08:55, 8 February 2018 (UTC)
 * I agree that the article can still be improved, but I think adding the example is an improvement because the previous state was suggesting that eating nuts or beans leads to an amino acid deficiency.
 * I would have like to add some text making the point I think you're making, that such an amino acid deficiency is very hard to create in real world conditions because a protein source can fill the gaps in another protein source, and our liver stocks the essential amino acids so that this compensation can be performed by foods that were eaten days or weeks ago. But I didn't have time for that edit and I expected it would be reverted.
 * So I figured the problem of the incorrect suggestion that eating nuts or beans leads to amino acid deficiency could at least be lessened by providing an example showing the problem goes away by eating an extra spoon or two of beans. The article could be better, but I think this is at least an improvement over the previous version.  Great floors (talk) 11:03, 13 February 2018 (UTC)

Dear Hempfan, please reply
Ok, I've been reverted again. Again, no reason has been given.
 * I explained my edits in the edit summary.
 * I made each edit separately so it's easier to see what happened in each diff.

I got reverted with no explanation.


 * I commented on Hempfan's UserTalk page to ask for discussion.
 * I explained my edits further here (above) on the Talk page
 * I waited a week.
 * I watched Hempfan actively editing other articles during this week but ignoring me.

I reinstated my edits, and got reverted again, with no explanation again.

How long do I have to wait for your comments/blessing Hempfan? Great floors (talk) 09:00, 8 February 2018 (UTC)
 * Ok, it's been 13 days with no participation from Hempfan, just two reverts with no reason given either time. My two comments on his user Talk page, and my two comments on this Talk page have been ignored.  I've reinstated my edit. Great floors (talk) 11:03, 13 February 2018 (UTC)
 * I've barely been active in editing this year. I was working on a long reply, but I lost it after my browser crashed. In any case, your contribution to this article is very inferior, and actually pointless, and not sourced. It's like you just wanted to throw in some edits just for the heck of it, just to increase your edit count or something. For one thing, you removed the sortable columns. Why? That's standard on Wikipedia, to have them sortable. And it's useful to have the various scores, amino acoid amounts and other numbers, sortable here. Then you removed the boldened text on the amino acid names and all that, again, why? I copied these tables from other Wikipedia articles, and that's standard wikitables. This edit, is also totally unsourced, which is ironic when you yourself, removed a section because it was "unsourced". Your unsourced edit is arguably original research too. The point about protein quality isn't whether or not you can meet the daily methionine requirements (or any other EAA), but that a protein source is deficient in the required amounts, per 100 g protein. Yes, you can eat tons of soy and get more than enough methionine, but soy protein is generally always slightly deficient in methionine. I find every edit you've made to this article, unacceptable. And that's not me being aggressive, it's just that you haven't improved this article in any way. And just because I haven't replied doesn't mean I've accepted your edit. I suggest you revert back to the last version. HempFan (talk) 07:52, 18 April 2018 (UTC)
 * I didn't make the columns not sortable. They are sortable.
 * I removed the bold formatting, and the letter "g" from every column too, because both unnecessary and were making the table wider - when it's already too wide to fit on most screens
 * My unsourced edit contains data from the table and some obvious, widely-known stuff like that the liver stores amino acids. If there's a part that you disagree with (like, if you think our livers don't store amino acids) then remove that part or add a tag requesting a reference.  Reverting is not the right tool.
 * "you can eat tons of soy and get more than enough methionine" - this is the type of confusion I was clearing up. It's not "tons" (which I know means "a lot", not literally "tons"), it's a few grams.  If someone can see the table and think that someone eating soy beans would need a lot of extra food, then the clarification is clearly necessary.
 * Great floors (talk) 00:13, 27 April 2018 (UTC)
 * Great floors, you turned the headers for the table in the "Amino acid profile" section into regular cells. Since those headers are the the cells that contain the arrow icons used to actually sort the table, your change made the table de facto non-sortable. Try sorting it by the "Human breast milk" column in your revision to see what I mean. I'll restore that.
 * Regarding the "g", I don't think that's the deciding factor for any of those columns' widths. Unless I squeeze my browser window so much that "Human breast milk" becomes three lines, no column's width is limited by the "g". If it's omitted we would have to add some description to the table what those figures actually are, though. To me having the "g" seems easier and less ambiguous.
 * I don't agree that the additions are "obvious, widely-known stuff". I'd rather say that whenever an unsourced sentence begins with "It should also be noted", we're editorializing and expressing an opinion. "The risk of a deficiency is for a subject consuming only one type of protein over a long period" - particularly since this is arguably a medical claim, reliable sources would be needed to support it. I'll remove that.
 * Whether having to eat 14% more is "a few grams" is debatable. Unless reliable sources have commented on that question, it's not a debate to be held on Wikipedia. Huon (talk) 01:21, 28 April 2018 (UTC)
 * Oh, my mistake, I was looking at the first table. Before my edit, the table had sort arrows you could click on, but they ordered the rows: 1, 10, 18, 2, 21, 3 ...  The solution might be to put an invisible zero before he single-digit numbers.  I'm not sure.
 * For browser width, remember that tablets and smartphones, held vertically or horizontally, have narrow screens. I added the unit clarification in the table's title.
 * If something needs a reference, removing it is of course fine. I might try to find a reference.  Or you could tag the sentence as needing a reference. Great floors (talk) 01:35, 28 April 2018 (UTC)
 * @Huon, what what wrong with my edit to the first paragraph? Why revert that??
 * And the "complete protein" column, if you check the linked article you'll see it doesn't support the "yes/no" values in that column. There's no source at all.  Why re-add it??
 * etc. etc. Great floors (talk) 01:42, 28 April 2018 (UTC)
 * Regarding "g" and browser width, I missed that you did change the header, but I still don't see the benefit of doing it this way. If youre on a smartphone or tablet where the regular view becomes unwieldy, try the mobile view. That comes with line breaks; at worst the "g" will be shoved in a new line, but it won't affect table width.
 * I'd expect that the methods which are no longer in use indeed are outdated - "some of which are now considered outdated, others are no longer in use" suggests those are different groups. The "not considered as useful as they once were thought to be" part to me seemed a summary of the content on BV, PER, NPU and nitrogen balance further down in the article, so I re-added it.
 * The "Complete protein" column is the negative of the "Limiting amino acid" column: It's complete if (and only if) there is no limiting amino acid. That's pretty much the definition of "complete protein". Since you left the latter column in place, I don't see why the former would be unacceptable. Huon (talk) 03:02, 28 April 2018 (UTC)

Soy protein is complete (pea too)
I can see that no one is going to remove the "complete protein" section even though recently it is criticized a lot, but at least it should depict the correct verdicts about plant-based proteins. The table says that limiting amino acids for soy and pea proteins are meth+cyst, which is not true. Soy protein has 2.6% of meth+cyst of total protein that is more than required - 2.5% to qualify as a complete protein (see Complete protein for the guidelines and for amino acid profile of soy protein). Same is for a pea protein, which has about 2.54% of meth+cyst of total protein which just fits in the required amount. So I am changing the complete protein status of these two proteins. If anyone doubts about the numbers I say, please go to the above-mentioned resources and calculate it yourself. If there is another reason for why changes should not be made, I am open to it. Please do not revert the changes without explanation, since I truly want to know why soy and pea proteins are not regarded as "complete" :) — Preceding unsigned comment added by Dzaocom (talk • contribs) 19:09, 13 January 2019 (UTC)
 * Hi, nutritiondata.self.com isn't a reliable source because anyone can edit it, and moreover, it doesn't show the protein as complete; it shows if the amino acid profile is complete or not, but it doesn't report PDCAAS or DIAAS values, which is how we measure if the protein is complete or not. Now while some soy protein isolates do get a PDCAAS score of 1.0, meaning complete protein, soy beans typically get an almost complete PDCAAS value, at around 0.92, as reported in this article. Anyway, please use a more reliable source like usda.gov (which admittedly has issues of its own, but at least it's an authority). HempFan (talk) 05:17, 13 April 2019 (UTC)
 * Currently there is no reference for soy not being a complete protein in this article, but my edit https://en.wikipedia.org/w/index.php?title=Protein_quality&oldid=927833055 added a source that says it is. It is also the same source that is used in the "Complete protein" article that Dzaocom referred to, which is  https://en.wikipedia.org/wiki/Complete_protein#cite_note-10
 * Clearly, going from no reference to a pubmed journal reference is a more defensible position. If HempFan disagrees with it then a superior reference is needed to trump the one I added. SubJunk (talk) 22:33, 26 November 2019 (UTC)

In the complete protein section, none of the other protein sources are referenced there either in the yes/no field; the references are found throughout the article, mainly in amino acid score and the amino acid quantity from the USDA. There's plenty of references for soy not being a complete protein, for example, that soy only reaches 0.91 on the PDCAAS scale, and PDCAAS might even be superseded by DIAAS eventually, and soy is definitely not a complete protein source on the DIAAS scale either (also referenced). In any case, the source you provided, says that soy is a complete protein because it has all the essential amino acids. Well with the exception of gelatin, all protein sources contain the essential amino acids, so if we were to go by this, gelatin would be the only incomplete protein source. Obviously, a protein is complete if it contains the essential amino acids in sufficient quantities, as determined by amino acid score. And soy is slightly deficient in the sulfur amino acids. And then there's the digestibility factor to keep in mind, which makes all protein sources less complete. Keep in mind, that I really like soy protein and that I eat soy almost every day in one form or another. But it's just not a complete protein source. Most beans (if not all) are slightly deficient in methionine/cysteine, so it's not a soy thing, and that's not necessarily a bad thing either, because it's good for protein combining with other protein sources such as rice and so on. Anyway, soy's limiting amino acids, methionine and cysteine, are very much well referenced in the article from multiple studies and USDA. HempFan (talk) 12:23, 29 November 2019 (UTC)
 * The references you provided don't seem to support the things you wrote here - all 3 sources (https://academic.oup.com/jn/article/145/2/372/4585766, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5041535/, and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3905294/) say that soy protein has up to 1.0 PDCAAS score, but can be lower (as can the other things like whey).
 * It may be most accurate to say it is sometimes "complete", given the range of PDCAAS values from 0.9-1.0. We could change the value to "Sometimes" and leave a note like "Soy protein isolate can have a PDCAAS value of less than 1.0 (Supro XF) or 1.0 (Supro 670), though it should be noted that using the DIAAS system instead of PDCAAS, it is not complete" which seems to match the information in the sources you provided. What do you think about that proposition? SubJunk (talk) 20:43, 8 December 2019 (UTC)

WHO/FAO not a reliable source?
Zefr, please explain why you removed WHO/FAO as a source, in this edit. Thanks. HempFan (talk) 18:30, 6 June 2019 (UTC)
 * I called the WHO source "unusable" because it is a long, out-of-date (1989) document onerous to use online. Its reference for pea protein content is difficult to find in the document. We should have a more accessible online and specific source (I couldn't find one). Also, when you add a ref, please don't just place an URL inside the ref tags, but take the time to fill out all the source details in a template; WP:CIT. --Zefr (talk) 19:43, 6 June 2019 (UTC)