The New Science Of Rapid Muscle Growth - Menno Henselmans

How much truth is there that your body can only absorb 20 grams of protein per meal? Because this is something that's been floating around for a very long time.

So this myth has a kernel of truth behind it, but the idea that the body can literally only absorb 20 grams of protein in a meal is outright ludicrous. The body can easily digest and absorb basically infinite amounts of protein in a meal, there is no practical limit. You'd have to be doing, like, massive food challenge, hot dog eating contest stuff. Even then, it's probably not really a limit. So the problem is that after the digestion and absorption of the protein comes the metabolism stage, and there is a limit to how much muscle protein synthesis the body can stimulate with a single meal, and that's called the muscle full effect. Now, it seems that if you ingest something like whey protein, which is very rapidly absorbed and very high-quality protein, in resting conditions when you are fed, 20 grams of protein seems to pretty much maximize muscle protein synthesis over the span of a few hours. However, when we start looking at mixed meals, when we start looking at post-workout conditions, protein sources that are not super high-quality, not whey protein, things that are matched with fiber, you know, meat, for example, which is much more slowly absorbed, then we see that the absorption limit changes, or the, the maximum productive amount of protein that we consume in a meal goes more up to 80 grams, at least 40 grams, and in a recent study, seemingly even 100 grams, at least if that's pretty much your only meal for the day. So it seems that the body's quite flexible in how it handles protein. If you fasted beforehand, if you had a workout beforehand, the body can use more protein because it wants to build more muscle. So in that sense, the body has adapted, evolutionarily speaking, well to using the protein when there is indeed a demand for muscle protein synthesis. Like, you can't just eat your way to the Olympia. You have to actually stimulate muscle growth, and then the protein will be used for muscle protein synthesis.

Right, so when people were saying you can only absorb 20 grams of protein per meal, what they meant was that was what your body can utilize for mus- muscle protein synthesis, and that seems to have a ceiling which is raised through exercise, through a scarcity of protein over the last period, 24 hours, 20, whatever, 30 hours, something like that, uh, and also presumably androgens, whether or not-

Yes.

... you're on testosterone.

Yes. So we have this thing called mTOR, which is a master enzyme, and it integrates all of the signals for protein synthesis. Essentially, it looks at all the factors that govern whether this person needs to get very jacked or whether we are okay with minimal jackedness. And if this person is on a boatload of testosterone, there are lots of amino acids floating around in the blood, and you have thoroughly trashed your muscles with a workout beforehand, then mTOR is maximum effort. If, on the other hand, you are rested, well-fed, you have not worked out, then mTOR is like, "Eh, we're gonna keep it at this level."