Understanding amino acid requirements

Hi,
Today I was reading "Protein and amino acid requirements in human nutrition" document from WHO, and I found this table:

I checked and it seems Cronometer use the requirements from the first column (mg/kg/day). But I don't understand what is in the second column (mg/g protein). It's another method to calculate the daily requirements ? If so, then, why they are two ? And which is best to use ? So confusing...
Let's take for example Isoleucine. I have 75kg, 2300 kcal/day, 100g protein/day (18%).
Using first column: 20mg/kg => 20 * 75 = 1500mg/day.
Using second column: 30mg/g protein => 30 * 100 = 3000mg/day.
So you see... there are very different values.

Comments

  • Ok, I have another problem.
    With my 18% ratio of protein I must consume about 100g. Recomended protein intake beeing 10-35%, I think 18% is not very much. But my amino acid targets are 200-300% oh most of the days. So how can I make my protein target if I must limit my amino acids intake ?

  • @Marus ,

    Your questions are sure getting me to dig into my biochemistry knowledge! ;)

    You should be using the first column to calculate absolute amino acid requirements; the second column refers to dietary patterns (i.e. the number of mg of amino acid per gram of protein needed to meet requirements on a mixed diet).

    Your actual protein needs would only be 0.8 g per kg of healthy body weight = 60 g per day (based on the RDA). What 10-35% refers to is the Acceptable Macronutrient Distribution Range and is the number of calories derived from a macronutrient that can be consumed without risk of under or overconsumption. Your amino acids are showing high because you have well surpassed your minimum intake of protein.

    Finally, try to think about protein and amino acids as somewhat separate from one another since it's possible to meet your protein intake, without meeting all essential amino acids.

    Let me know if this makes sense!

    Kind regards,

    Susan

    Susan Macfarlane, MScA, RD
    Registered Dietitian Nutritionist
    cronometer.com
    As always, any and all postings here are covered by our T&Cs:
    https://forums.cronometer.com/discussion/27/governing-terms-and-disclaimer

  • I do not understand.
    0.8 g/kg it's a standard for all people ? Like for a sedentary man and a bodybuilder too ? Most internet articles which I have read say it is not. They say if you have a high activity level you should consume more protein. But that doesn't make sense either, because if I increase the amount of proteins, I exced the RDI of amino acids, which are fixed (ony varies with wheight, but not with activity level).

  • @Marus

    I know it can be very confusing! :smile:

    The RDA sets a protein recommendation of 0.8 g of protein for healthy populations. This doesn't include athletes or those that are highly active. Clinical practice guidelines recommend a protein intake of 1.2 - 2.0 g per kg of body weight for highly active individuals and athletes, depending on the sport.

    I'm not aware of specific amino acid recommendations for athletes and highly active individuals, other than the need to include "high-quality protein sources" (i.e. meat, eggs, dairy, soy, etc.). It's likely that amino acids do increase for athletes, although, as mentioned, I haven't seen a specific list of amino acid requirements for athletes based on activity level.

    Let me know if you have any follow-up questions. :)

    Kind regards,

    Susan Macfarlane, MScA, RD
    Registered Dietitian Nutritionist
    cronometer.com
    As always, any and all postings here are covered by our T&Cs:
    https://forums.cronometer.com/discussion/27/governing-terms-and-disclaimer

  • It looks like the challenge @Marus is facing is seeing the amino acids RDI as the maximum one should take, when they should be the minimum, and in normal circumstances exceeding them shouldn't have toxicity issues like with some vitamins and minerals. On a good day I take in some 500-1000% of each aa, but most of the time they're from real food so I'm not too concerned.

  • No, Vickie, I am aware that those amino acids RDI are the minimum requirements, but I found a document from The National Academies of Sciences Engineering Medicine which contains tolerable upper limits for amino acids. And they are 2-3 times higher than RDI. See the page starting with 696.
    But they say again that... : "There is no evidence that amino acids derived from usual or even high intakes of protein from foodstuffs present any risk. Therefore, attention was focused on intakes of amino acids from dietary supplements and when utilized as food ingredients, such as monosodium glutamate in food or aspartic acid and phenylalanine in aspartame."
    So, I am somewhat relaxed now. :smile: Especially that Susan said 1.2 - 2.0 g protein per kg of body weight is normal for verry active people.

  • @Marus

    Your research is excellent! Everything you cited was very credible. Glad everything has been sorted out!

    Kind regards,

    Susan Macfarlane, MScA, RD
    Registered Dietitian Nutritionist
    cronometer.com
    As always, any and all postings here are covered by our T&Cs:
    https://forums.cronometer.com/discussion/27/governing-terms-and-disclaimer

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