Hello, and welcome back to the Ideal Nutrition podcast. My name is Aidan Muir and I am here with my co-host, Leah Higl. And this is episode 46. And today we are going to be talking about things that are useful to know about protein and muscle growth/retention. So I basically categorize it into [00:00:30] four key areas or four key things you need to think about when you think about protein. So there’s total protein intake, distribution of that protein across the day, protein quality, and then also specific timing. And I also view it almost like in a hierarchy where you want to think about them in that order, whichever protein is the most important thing, then distributing it across the day is something that matters, but matters significantly less than total protein intake. Quality matters, in most cases, it’s going to take care [00:01:00] of itself to a certain degree. If you’re having a wider variety of protein sources and you’re having enough total protein intake.
But what if you aren’t or what if you’re in a specific situation, for example, maybe plant-based diet or something like that, where it starts to matter more? And then specific timing is important too, but if you are distributing it across the day, that could also potentially take care of itself as well. So that’s how I think about, arguably all of them matter, but we would want to be prioritizing it in that order. Did you want to start with [00:01:30] the most important one, total protein intake?
Let’s do it. So obviously the most important factor like Aidan said is total protein intake and doing that consistently day to day. It is super important to be aware of the fact that this is like of number one most importance, because sometimes it nullifies like arbitrary rules people will put on protein intake. So a really common one is, ah, you can only absorb 30 grams of protein every three to four hours [00:02:00] or like per sitting. So the research shows that for relatively lean people wanting to optimize muscle growth, we want to be aiming for between 1.6 to 2.2 grams of protein per kilo body weight per day. So that’s what the research shows would be optimal for muscle growth. If we do the mass on that.
So let’s take an 85 kilo athlete. If they were sitting within that range of protein intake, that would be 136 [00:02:30] to 187 grams of protein per day. That would be an optimal amount for them. But if we limited it to 30 grams over say four meals across the day, that would mean they’re only getting in 120 grams of protein per day, which we know they would, based on the research, benefit from more than that. So like 140 grams plus per day. So knowing that is the most important thing in regards to getting enough protein per day, it can [00:03:00] help you wade through like random rules other people kind of put in place when it comes to protein.
Yeah. And even that rule, like I do think a lot of people haven’t sat down and thought about it really critically when they’re talking about that rule because, firstly intermittent fasting is quite popular. People who do intermittent fasting aren’t dropping muscle like crazy, particularly when calories and macros are matched. When they’re [00:03:30] having the same calories and the same protein, the research under the circumstances of a calorie deficit, which almost every time somebody’s doing a fasting style approach is going to be in a calorie deficit. The research on that topic shows that they’re retaining muscle pretty much just as good. And that’s not possible if we could only absorb “30 grams every three, four hours.” In that case, it should be vastly superior to be having four to six or however many protein feedings “across the day”.
And even just [00:04:00] like, I hate using the evolutionary kind of example, but I have to do it. What about when we didn’t have access to food around the clock, that hunter gatherer lifestyle would really have struggled if we could only absorb 30 grams of protein, but we only got to eat large amounts of protein, very infrequently. Now looking at it from the opposite perspective, that arbitrary rule doesn’t come from nowhere, it does come from somewhere. And that is why distribution of protein intake does matter. [00:04:30] So where that often comes from is that these studies are often measuring muscle protein synthesis in an acute kind of time frame after consuming protein, whether that’s post-workout or whatever. And typically the limit is somewhere between 20 and 40 grams, depending on the size of the individual, someone who’s quite small, 20 grams might be where it’s maximized, somebody’s larger, 40 grams might be where it’s maximized.
Even that research has some outlier situations like older individuals who’ve just done a full [00:05:00] body workout, like when they have done that research, sometimes it goes up as high as 70 grams.
So like an arbitrary cut off like 30 grams like it doesn’t apply in all situations, but that’s just measuring muscle protein synthesis. That doesn’t mean that it’s necessarily a limit on how much it’s going to be used for muscle growth over the longer term or anything like that. We don’t really care that much, although it is useful from a mechanistic perspective, we don’t really care that much about acute measures of muscle protein synthesis. We care about muscle growth. We care about muscle [00:05:30] growth over time. And we actually do have longitudinal data on this topic. And the best review on this topic that I’m aware of is done by Brad Schoenfeld and Alan Aragon on where they concluded that the best approach to aim for would be 1.6 to 2.2 grams per kilogram of body weight, protein per day as you mentioned earlier, and ideally to achieve that by having 0.4 to 0.55 grams per kilogram of protein per meal, over a minimum of four meals. [00:06:00] So what they’re saying is do both.
And they start with have this minimum amount of protein and then spread it out evenly kind of across the day. And I think saying it that way is it’s definitely the way to go about it because you want to get that maximum amount of protein in that like optimal amount and then split it up evenly not try to do it the other way when you’re just trying to get in. If you splitting it up throughout the day means that you are getting less total protein intake and it’s below that optimal range. You’re doing it wrong.
[00:06:30] Yeah. One of the reasons I really talk about this a lot is because one of the first rules is do no harm, like somebody who is following “pro-science” or something like that, and is just having protein around the clock like heaps higher amount of protein and you tell them to limit to some arbitrary number, you’ve done the one thing that makes them worse. Like you’ve done, you’ve literally reduced their results. The first rule is do no harm and then we’re trying to get like better results from there. [00:07:00] So it’s like that is an important thing. And then as I can, as I said, I only really care about outcomes. Like I don’t care that much about mechanisms, but it is useful to think about like, why could this be the case? Why does total protein matter far more than that muscle protein symptoms kind of data.
And one of the interesting lines from that review from Alan Agon and Brad Schoenfeld was consumption of slower acting protein sources, particularly when consumed in combination of other macronutrients would delay absorption and thus conceivably enhance the utilization of the constituent amino acids, [00:07:30] which basically means like when you consume large amounts of protein in mixed meals, what if they’re slower acting ones like for example, casein or something like that, it doesn’t really matter what happens in the hour post consumption. If you are still digesting it hours later, it can still be utilized over a longer period of time. Maybe that muscle protein synthesis is elevated for longer and it can be utilized for that. There’s a lot of factors, but either way, we know if you want to optimize muscle growth aim for four to six meals with greater than 20 to 40 grams of protein depending on size [00:08:00] is the best approach.
But just because people care about this, like three is almost as good as four. That’s really important information. You don’t want to get caught up on the four to six, the difference between three meals and four meals, continuous meal protein is so, so small that if I’m working with somebody who wants to absolutely optimize muscle growth, it’s going to be four to six every time. But the moment somebody’s lifestyle gets in the way and they’re like, “I just want to grow muscle. I don’t care if it’s like a hundred percent optimized.” It’s three, it’s no brainer.
Yeah. Just cause it’s [00:08:30] such a small difference it doesn’t really matter. Whatever’s logistically more possible for that person probably makes more sense. The third piece of this puzzle is going to be protein quality. So I’m going to take a quick detour on amino acids. So protein is made up of amino acids. A lot of people like to say, it’s the building blocks of protein. There are 20 amino acids, nine of which are essential, meaning that we can’t create them with our own bodies. We have to get them through our diet. Three of those [00:09:00] are called branch chain amino acids, which are the most strongly linked to muscle growth. And then one of those is called leucine, which we know is quite good at triggering muscle protein synthesis and is one of the most linked, like singular amino acids linked to muscle growth and is really important in talking about protein quality.
So I’m going to break protein quality up into three separate components. So let’s start firstly with leucine as a good starting [00:09:30] point. So ideally for muscle growth, we’re looking for sources of protein are a good source of leucine as well. So ideally in those bouts of protein throughout the day, we want about two to three grams of leucine each and every time to trigger muscle protein synthesis and to optimize it as well. So we call this like the leucine threshold. Most animal proteins are going to pretty easily do this. If you have 20 to 40 grams of protein [00:10:00] coming from animal sources, highly likely that you’re just going to hit this leucine threshold naturally. The issue is when we’re talking about plant based diets, that can then become a very difficult thing to do because soy foods are really our only good source of plant-based leucine. If we’re talking protein from greens and legumes, they’re all pretty low in leucine. So it’s going to be difficult to optimize muscle protein synthesis if you’re relying on those, just from a leucine perspective.
[00:10:30] The second part of it is talking about overall amino acid profile. So you’ve probably heard the concepts of incomplete amino acid profiles or incomplete proteins and complete proteins. So this does refer to the overall quality of the amino acid profile and how good it is at optimizing muscle protein synthesis. So from the perspective of animal foods, most are going to be quite high quality proteins, because they’re going to be complete [00:11:00] proteins. An exception to that rule would be gelatin or collagen, which we know doesn’t have a very good amino acid profile for muscle building, but most other animal sources are going to be quite good. Once again, plant-based foods tend to be your incomplete proteins. So not only is soy good for leucine, it’s actually one of the only complete proteins that is plant-based. All the other plant-based proteins are missing or low in [00:11:30] one or more amino acids that make them not the best quality for muscle building.
Generally having a good mix of protein sources throughout your day and throughout your week is going to overcome most of this. But if we are looking to like optimize things to the end degree, when I’m working with plant-based athletes wanting to build muscle, I tend to do protein combining within meals as well. So not just over the course of the day, but within meals. So that’s taking two sources of protein that are [00:12:00] lacking in certain amino acids, but they’re complementary. So one is low in a certain amino acid, but another source is high. So you’re combining them together to create a more complete amino acid profile. So that is one way you can overcome that on a plant based diet and like really optimize things. But if you’re getting most of your protein through animal foods, not really something that you’re going to have to think too hard about.
The third aspect of [00:12:30] protein quality is going to be digestibility. So the amount of protein digested and absorbed from different protein sources does differ. Once again, animal proteins tend to be really digestible. So as a whole, your animal proteins are often going to be your highest quality proteins and the best for muscle building. And then your plant-based proteins do tend to be less digestible, particularly the less processed they are. So things like [00:13:00] your legumes are going to have a pretty low digestibility score. Whereas like things like tofu might be a little bit better because they have other nutrients within these foods that are preventing some of that absorption from occurring. So quality is pretty complicated, but at the end of the day, if you’re going for animal proteins, I wouldn’t worry about it. If you’re plant based, you need to think a little bit harder.
Yeah. And this is exactly why I view it in terms of that order of priorities, where it’s like, you’ve got the [00:13:30] total protein, then you’ve got this distribution and then protein quality is third. Because, if you didn’t think about it in this order, you could get misled, like for example, eggs, one of the highest quality protein sources based on quality of protein, like biological value, which is like a measure of amino acid and how that relates to muscle growth and everything like that. Stuff like chicken, beef, all these other ones, they’re they’re around that a hundred kind of level as well, out of a hundred, like [00:14:00] they’re quite high.
But what if one version of you got two eggs, which is 10 grams of protein and it’s a really high quality protein. And the other version had 40 grams of protein, which was a slightly lower quality, but is significant me more protein and gets you closer to that. 1.6 to 2.2 grams per kilogram, body weight per kilo range. The one getting more total protein is probably going to get better outcomes. Both matter, but total protein matters more, [00:14:30] which then feeds back into like everything you just talked about. Like that was a lot and it is far more relevant for plant based. It’s still kind of relevant for animal based, but it is far more relevant for plant based. One solution is some of the things you mentioned and then also having higher total protein intake and then just having an abundance of amino acids
Totally honestly, when I’m working with my plant based athletes, I just take that general protein recommendation that we talked about at the start. I add 10 to 20% to it and that’s [00:15:00] most of my work done.
And we don’t worry too much about all this other stuff. We might have a bit of a focus on soy foods.
But that’s pretty much the biggest two things I do.
Yeah. And another option, which like I personally don’t use with clients who are plant based, but it is something to consider is BCAA supplementation. Theoretically, each of the BCAAs is going to have that two to three plus grams of leucine and like having that alongside some of your lower leucine meals could make sense [00:15:30] as well.
Another thing I’ve done is just literally supplement with leucine. Particularly for such a specific niche scenario, but a plant-based athlete that had a soy allergy wanting to optimize muscle building.
We were supplementing leucine, but outside of that, I really recommend it.
Yeah. For sure. So this stuff matters. Yeah. You just don’t want to get mixed up, I guess. And then that also feeds into specific timing. So examples of specific timing that people talk about as being important is little things like having quick [00:16:00] digesting protein post-workout for example, whey protein or slow digesting protein before bed, for example, casein. Shout out to my housemate Rock. So he refuses to work out when he doesn’t and have whey protein available because he doesn’t want to waste his gains. It is a thing.
A lot of people think it’s really, really important. It’s like this concept of post-workout protein. Like some people view this anabolic window as the most important thing. There is a swing of the pendulum in the other direction and [00:16:30] probably not as much anymore, but I did see it on forms like bodybuilding.com and stuff like that in the evidence based community on there where people like, nah, protein timing doesn’t matter. If it fits your macros, as long as you get your total protein for the day, that’s all that matters. And like most things in nutrition, the answer is somewhere in the middle. It does matter, but it’s not like, Hey, if you work out and don’t get your protein in directly post-work you’ve ruined all your games. It’s not like that. You still make great progress.
I have to say, I used to think that when, before, when I was in high school yeah. That was my [00:17:00] train of thought.
Gotta rush home and get your protein shake.
Yeah. For sure. No time to shower after your session
Yeah. When we’re talking about anabolic window. So once again, it’s another review by Alan Aragon and Brad Schoenfeld. They called it nutrient timing revisited. And it was in 2013 and the research hasn’t really evolved that much since then. So, which is why I still cite this study. They looked at all of the research that was available on this topic and came to [00:17:30] a conclusion that it’s still probably beneficial to have some form of protein around three to five hours around the time of your workout, either before or after. So view it as like a window and the five hour kind of window is really mostly relevant if you’ve had a really large protein portion, a couple of hours before you train. Because as we spoke about earlier, if you have a large amount of protein, it takes while to digest. If it’s a mixed meal, large amount of protein has carbs, has fiber has all these things that slows it down. It’s still going to be affecting your muscle [00:18:00] protein synthesis post-workout, which is why you can have it before.
If you were to train faster than the other end of the spectrum, you’ve probably only got like a 1.5 hour kind of window post-workout to get it in. The anabolic window suddenly would be far more important if you were training faster, not super important, less important on all these other details, but it would be relevant. And the concept of the anabolic window is it’s just this window where it’s like muscle protein synthesis is elevated more significantly and you want to be feeding more protein during that timeframe. Do you have any other thoughts [00:18:30] on the anabolic window or before I go into other stuff?
No, just that people give it way too much power most of the time. It’s not, to be honest. It’s not that important. It’s just like, that’s why it’s the last thing we’re talking about because it is the least important thing.
Yeah, for sure. And I guess that’s one of the reasons why it’s a bit less important is if you do one of the criteria you mentioned earlier of having say four to six decent size protein meals/snacks throughout the day, you’re going [00:19:00] to be eating in that window [inaudible 00:19:01] without even thinking about it. That’s not to say it’s not a bad habit to actually have protein post work because if you do that every time, you’ve already got the habit and you guarantee that you do it, but you probably don’t even really need to think about it that much. The other kind of concept is like whey versus casein. Whey is quick acting, casein is slow acting. So there is one study I’m aware of where they literally just compared whey protein versus casein protein, post-workout. Longitudinal [00:19:30] data. So they just measured muscle growth over multiple weeks. They got the same outcomes.
And it just breaks like that whole philosophy because it’s like, theoretically, wouldn’t you really want a rapid acting one. And maybe it’d be different if you were training faster in that study. I don’t believe that they were, but so it’s clearly not a massive priority. And that’s why we talk about total protein mattering far more. But then the other one is casein before bed and the logic is sound. It makes sense to a certain degree. If casein is slow digesting and you’re about to fast for eight hours, hopefully because you sleep eight hours [00:20:00] I hope, ideally in a perfect world. If you’re going to fast for six plus hours or five plus hours or four plus for some parents, ideally you’d want to be having slow acting protein while you’re sleeping. It’s the kind of logic there. But once again, it just does not seem to matter.
There are a lot of studies done under suboptimal conditions. For example, they will have quite low protein intakes. Like they’ll get a larger person and give them a small amount of protein. And the quality seems to matter on lower protein intakes and timing seems to matter [00:20:30] a little bit more on lower protein intakes as well, or in some really broken studies, they’ll give the casein group more total protein. They’ll give both groups the same amount of protein and then give someone casein before bed. It’s like, well of course they gain more muscle. Like
They’ve got more protein. They had a suboptimal protein intake before, they’ve got less suboptimal protein intake now. And that makes sense. But when all other things are equal and your total protein is high enough, it’s spread out across the day. It does not seem to make any difference. Otherwise, I’d be getting all of my clients to do it because I want to help people build muscle. Yeah. If it helped, I would [00:21:00] get people doing it. When you listen to all of this, it’s like, it makes it seem like you need to be consuming protein around the clock, but you don’t really need to. It seems like the process can be optimized with like a 10 to 12 hour eating window. That’s not quite fasting, but it’s also not quiet. The second you wake up, you need to have protein, right before bed, you need to be eating protein. It’s not like that. You can have a bit of a gap before bed or after you wake up if you want as well.
So it’s not super urgent. And as I said, I really just care [00:21:30] about outcomes. I don’t care about mechanisms as much, but one of the pieces of logic that goes into that mechanism is muscle protein synthesis is only one portion of that kind of equation. We need muscle protein breakdown to occur, to facilitate new muscle growth as well anyway. So that’s part of why we don’t necessarily need to be consuming protein around the clock. Although having a decent sized eating window where you’re spreading protein out throughout the day is still helpful.
So at the end of the day, total protein intake is the number [00:22:00] one most important thing we want to do. So trying to get between that 1.6 to 2.2 grams per kilo body weight per day ideally, we want to distribute it evenly across the day ideally again. Four to six meals, but lesser of a priority than total protein intake. Ideally we’re getting it from high quality sources and ideally some around our training as well. So this has been episode 46 of the Ideal Nutrition podcast. If you’re able to do [00:22:30] so, we’d love a rating and review if you could leave one, but otherwise thanks for tuning in.