There is a big difference between animal protein vs plant protein which isn't talked about very much so I'll mention it here so people can make a more informed decision.
The
Protein Digestibility Corrected Amino Acid Score (PDCAAS) is a method of evaluating the quality of a protein based on both the amino acid requirements of humans and their ability to digest them.
The highest PDCASS score is 1.0 which indicates the amino acid profile and digestibility it provides is 100%. For example an egg has a score of 1.0 (100%) vs wheat for example which has a score anywhere from 42 to 50, both the amino acid profile and it's digestibility value is about half as much as an egg. So it's important where we get our protein as well.
There's a few reasons for this difference.
1)
Amino acid composition, wheat for example is deficient in lysine which also helps absorb calcium for bone health, contributes to collagen production and supports the immune system.
2)
Antinutrients, wheat contains antinutrients like phytic acid which has a strong binding affinity to a few minerals which are calcium, iron, zinc and magnesium as well as reducing the digestibility by inhibiting some digestive enzymes.
3)
Protein structure, particularly gluten which is a very complex structure making it resistant to proteolytic enzymes in the gut making it less bioavailable and absorbable.
If someone is mostly plant based then soy and chickpeas are your best source of better quality amino acids and absorbability with soy scoring 91 and Chickpeas 78.
The USDA understood the difference but have never shared that to any extent with the general public and considering most people are omnivores it would just complicate things, but buried in the few hundred pages of the USDA literature they gave the reason why. The USDA instructs people to consume half of their grain products in refined carbohydrates, like bread and breakfast cereals and told us to eat 7 to 11 servings a day which then could be fortify with those minerals and certain vitamins that are missing and would have been unavailable biologically if people ate all whole grain. I remember count chocula, back in the day and it even came with with that health blue check mark form the AHA, remember those, telling us it was going to save us from heart disease, the good ol times, lol.
Anyway if your diet is mostly plant based it would be a good idea to do further research so you can make any adjustments if your so inclined to do and considering we need not only more protein as we age the quality is important as well.