You have to stimulate M4 but you need a certain amount of lucine to do it, as well as a full compliment of amino acids. You also need to have enough calories, it doesn’t have to be too much, but you have to have enough.
So when looking at what’s the best way to get your lucine in? It’s clearly going to be that the indispensable amino acids are going to come from animal sources.
Therefore, if you want to maintain your muscle mass outside of animal nutrition, you’re going to have to eat even more protein to do that in order to get the right amount.
It’s like building a car out of car parts versus computer parts. Yes, you might be able to scrape together enough plastic and metal parts out of a computer but you’re going to need a hundred times the amount of computers than you are with a car that’s already sitting there.
Now, if we have a look at how to best stimulate mTOR, in regards to longevity… first, let’s think about what’s the absolute best source of protein that you’re going to need to do that, because you’re still going to want to stimulate mTOR.
Our muscle building capacity revolves around mTOR so you want to do that and you can couple that with resistance training or something that stimulates muscle growth, versus too much excess of mTOR stimulation through excess of calories, excess of insulin, the wrong types of protein and then perhaps stimulating mTOR in tissues where we don’t want to stimulate it, like our liver and such.
So when it comes to longevity… yes, it’s more nuance to think (just like anytime we learn something new), ‘oh my gosh, mTOR seems to be related to problems with growth and overgrowth and cancer and we got to make it zero!’
But the human body is far more complex than any of us ever imagine, and it’s not binary like that, you can’t just shut something off completely and expect good things to happen.
Source: Baker, Shawn, guest. “Part 47 – The Great Meat Debate w/ Mark Sisson, Dr. Paul Saladino, & Dr. Shawn Baker” Peak Human, 18 July 2019. https://www.peak-human.com/home/the-great-meat-debate-with-mark-sisson-dr-paul-saladino-and-dr-shawn-baker