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Comment by aucisson_masque

2 days ago

Protein from grain food isn’t as well absorbed as protein from meat, milk, fish. Roughly, 2g of protein from bean equal 1g meat protein.

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aucisson_masque

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ctoa  2 days ago

Yes, but the standards aren't based on "the best protein to absorb", they are based on whole diet consumption. Studies like the one I linked to are where the recommendations come from. It is a misunderstanding to read a recommendation for 1.2g/kg (or whatever) as saying that the 1.2g is supposed to all be meat quality protein. It's supposed to be the protein in your total mixed diet.

Your diet contains many sources of protein lower quality than beans (as in the linked study with high level Dutch athletes getting 19% of their protein from bread), you do need to count those. They do add up and if you don't, you end up assuming you need way more protein than you do.

  • aucisson_masque  1 day ago

    but then how do you know how much protein you should eat ?

    if I'm eating bread, pasta and other cereals, I may exceed the 1.2g/kg recommendations but the PDCAAS (Protein Digestibility-Corrected Amino Acid Score) of these would make it in truth closer to 0.6g/kg.

    Someone else eating mostly meat would get in total 1.2g/kg protein but also 1.2g/kg when PDCAAS is accounted for.

    Maybe it's to simplify the calculation to the average user but it feels misleading, you can't know for sure the proportion of cereals in somebody diet.

    • ctoa  1 day ago

      Well, that's exactly the problem with focusing too hard on one macro nutrient recommendation out of context of other balanced diet recommendations.

      Adding lean meat, dairy, eggs to protein poor diets is good, I love all of those things. Trying to hit a high protein target and understanding this to mean having to eat all or mostly meat is simply over correcting in a different direction.

      And meat isn't a perfect PDCAAS! Beef is 0.92 close to soy at 0.91. Milk, eggs, soy protein (isolate), whey are 1. Beans are 0.75.

      There's even more nuance, beans are partly lower because they are low in methionine, the essential amino acid that adults needs far less of than any other amino acid and that you don't need more of. In the context of a whole diet, it's not 92% of every gram for beef and 75% of every gram for beans, it doesn't work that way.

      Relatively small servings of animal foods add up to a lot of protein, like some other comment was freaking out about needing to eat 4 hamburgers or a 16 oz steak to hit the (very modest) goal of 90g in a day. But something like, 1 egg + 1 can tuna + 1 serving Greek yogurt == 42g, is already at half the goal, much of the rest of it will fill out just fine from a balanced set of other non-empty calorie sources.

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