This is an interesting article that discusses the longevity genes and the amount of optimal protein one should eat, depending on age:
https://www.mindbodygreen.com/articles/ ... -swears-by
(Note, though, the article is generally an excerpt from a book it references so that's why it seems to just cut off suddenly at the end!)
I had heard about varying one's protein intake depending on age, but couldn't recall what the amounts were so I did a search and found this article which sums things up pretty well:
https://www.bodyandsoul.com.au/nutritio ... 670db2ed9e