Non-animal based protein sources mostly have a different amino acid profile than animal-based protein sources. Different plants also have a different composition.
From looking a bit at the data myself it seems that if you mix different plant protein sources, you can get a good balance for most amino acids with the expectation of Methionine.
Mike from Renaissance Periodization who’s a professor of exercise science suggests that a vegan can just look at the Protein digestibility-corrected amino acid score (PDCAAS) and use this as a factor for protein consumption to get the correct amino acid consumption as a vegan.
From thinking about the issue myself, I would expect that you get significantly lower Methionine consumption if you do that then a person who uses animal-based products as their protein sources.
Given that a protein needs a very exact number of each amino acid to be synthesized, for essential amino acids like Methionine, I would expect their consumptions to be a bottleneck for muscle building which needs protein. Even if all the other proteins are in good amounts and thus the PDCAAS score is decent, you can drown in a river that’s on average 20cm deep.
One possible solution would be to focus on high Methionine protein sources as a vegan and less on the PDCAAS (for a vegan protein source, soy is good at both) and just consume twice the amount of protein that a non-vegan would to get similar Methionine consumption. I’m not sure what the exact consequences of having all the other amino acids in excess happen to be.
Has someone thought more about this and come to a good conclusion about how to think about Methionine as someone with a mostly vegan diet who wants to build muscle?
I could be misreading but it sounds like you’re misunderstanding how PDCAAS works. If a food contains lots of every other essential amino acid but only (say) 30% of the required amount of methionine, then its PDCAAS will be 30. If the PDCAAS is (say) 90%, that means it contains at least 90% of the requirement for every essential amino acid, not just 90% on average.
Methionine restriction has been shown to increase mean and maximum lifespan in various organisms, particularly rodents. Studies show it can increase lifespan by 30-40% in rats and mice, with effect sizes similar to those of calorie restriction. The lower methionine content of plant-based diets should be seen as a plus rather than a minus, I think.
You can buy methionine pills or powder: https://www.amazon.com/s?k=methionine&ref=nb_sb_noss
I believe they make methionine via chemical synthesis so it’s vegan.
For me personally, I get most of my daily protein from soy so I don’t worry about methionine, but I do have some methionine pills for when I need them. I also have lysine pills which pair well with wheat protein.
Recently I was annoyed at how difficult it was to figure out the protein quality of my diet so I built a calculator: https://mdickens.me/2024/08/29/DIAAS_calculator/