Aidan:

Hello and welcome to the ideal nutrition podcast. My name is Aidan Muir and I’m here with my co-host, Leah Higl and this is episode 156 where we’re going to be debunking 10 nutrition myths in a rapid-fire fashion.

Leah:

So we’ll kick it off with a creatine based one and that is creatine causes hair loss. Now this myth is largely based on a small study on rugby players where there was an increase in the hormone DHT, but there is really no clear evidence around creatine increasing DHT and that leading to hair loss which is part of why it hasn’t really been studied thoroughly. For context, even just lifting weights increases DHT.

In this creatine study, DHT stayed within the healthy range the whole time regardless. So even though there might be somewhat of a link between creatine DHT and like exercise and DHT, it’s really nothing that we should be overly concerned about because it’s probably pretty unlikely that these things correlate.

Aidan:

For our next one, we’re talking through the myth for fat loss, you want to keep insulin as low as possible. This is based on the logic that insulin promotes the storage of fat, it’s part of its role, and also decreases the breakdown of fat. Solely focusing on that is a bit of an issue though. The mechanism from that perspective, that in isolation makes sense, but there are so many things going on in our bodies, multiple hormones at once, and you can still be losing fat even while insulin is in your system. There’s a lot of people who talk about insulin through this lens without even kind of acknowledging that not only is it possible to lose fat while insulin is in your system, it’s actually really common to be losing fat while insulin is your system.

But researchers found that when calorie intake is controlled, differences in insulin does not significantly affect weight loss. As an example, carbs affect insulin way more than fat does. If you were solely focusing on insulin, you would come to the conclusion that higher carb diets would make it more difficult to lose body fat compared to lower carb diets. But when researchers compared them with calories and protein match, there’s been no difference.

A classic example that I often point to just to kind of like drive this point home is there’s a study by Kevin Hall where both groups lost the exact same amount of body fat or very similar amounts of body fat, but there was a 22 % difference in their insulin levels. If we solely focus on insulin, that wouldn’t be possible. So that’s why I’d say like, well, insulin is a factor in all of this. If you’re looking to lose body fat, creating calorie deficit is kind of the key. We’re not really focusing just on insulin.

Leah:

Rolling into the next one, protein is bad for your kidneys. So in people with healthy kidney function at baseline, there is no real reason to believe that higher protein diets lead to declining kidney function. There is this kind of general logic that high protein diets put extra stress and strain on the kidneys. But when we think this through, it doesn’t really cut it to utilise that explanation in that we know exercise puts strain on the heart but we would never say exercise is necessarily bad for the heart in kind of general population because we know that often frequent exercise actually reduces the risk of cardiovascular disease and cardiovascular issues in the long term. So again, doesn’t really cut it there. And then we also have research that also consistently shows that higher protein intakes, again, do not lead to declining kidney functions in healthy populations.

On the flip side, in people with kidney issues like chronic kidney disease, that can get a little bit more complex because we do have guidelines that suggest a lower protein intake for those with chronic kidney disease and kidney issues in general. The worst that that condition is typically the lower we’d have to go. But even still, it’s not like the appropriate amount in that situation is still not super, super low. It’s just also not super, super high either. But as a general rule, it would be unfair to say that protein is bad for kidney function. We would just have to be mindful if there is already an existing issue with the kidneys.

Aidan:

So this probably won’t make the show notes. We try to like reference all of our research and studies and stuff like that in the show notes. But there is a study that I’m just saying off the top of my head. There was a study that I heard on Stronger By Science’s podcast where Eric Trexler was going through this big, big, big longitudinal study where they compared like 40 years of protein intake where it was like low, semi -low, moderately high and quite high, not super, super high, but quite high protein intakes.

Then they just measured kidney function over a long period of time. If higher protein intake was going to be worse for kidney function, you should actually expect in research like that with large sample sizes, which it was faster rates of declining kidney function in the groups of higher protein intake. That’s not what they found at all. In fact, it seemed like there was like, just no correlation.

Like it wasn’t even like a, they all came out the same. It wasn’t a linear reduction in kidney function. It was a bit all over the place. Like one of them was like the lower one, just from memory, like the lower one, I can’t even describe it. It basically just like, I’m sorry for that. Yeah. Yeah. I don’t know how you reference studies off the top of your head. But there was just no correlation. Like it was all over the place. Like some of the groups had a faster rate of decline than the other ones. And there was just no linear correlation whatsoever. So like, I don’t know. It’s just like, I think that’s one of the best examples is because like, obviously we love a lot of like controlled research in many ways, shapes or form, but that one is just such a simple thing being like higher intake, very long time, very large sample size, no reduction in kidney function. When you’re looking at healthy population, it kind of makes sense that we don’t need to be too concerned about that.

The next one we’re going to look at is if you have high cholesterol, you need to avoid eggs. This is a complex one. I often talk about this through the lens of there being two pendulum swings. One pendulum swing is that eggs are very high in dietary cholesterol. They’re one of the highest dietary cholesterol sources. Therefore, we would need to avoid them. The other pendulum swing is that almost all of the cholesterol in our blood is synthesised in our own body. We don’t care about dietary cholesterol. We care about the cholesterol in our blood.

The answer to a degree is somewhere in the middle. It is actually closer, I would say, towards that end of the spectrum where a large percentage of the cholesterol in our blood is synthesised in our own body. But that doesn’t mean that dietary cholesterol doesn’t matter whatsoever. If somebody has an exceptionally high dietary cholesterol intake, that is likely going to be a factor. Anyone with a high dietary cholesterol intake probably also has a higher saturated fat intake, which is also associated with cholesterol in the blood.

So my short kind of explanation of it is I wouldn’t necessarily say you need to avoid eggs. Technically, having a lower intake of them might help in certain cases with all other factors being equal, but it’s rare that all other factors are equal. I probably wouldn’t stress about it. A guideline that I’ve seen some health organisations put out is a limit of about 10 per week, and I don’t necessarily think that’s a bad guideline. just because I’m also big on variety, just being like if you’re getting above 10 eggs, you probably could have also been having a variety of other foods that come alongside different micronutrients and other benefits as well. So I think if somebody was concerned about this, I think that’s a pretty safe limit.

Leah:

The next one is plant-based protein sources are terrible for muscle growth. Obviously one that is quite close to my heart working specifically in the plant-based space and with athletes. But to kind of summarise this, research using highest protein intakes of like 1.6 grams per kilo body weight per day typically finds equally good outcomes for muscle growth in both acute and long-term data. So that’s pretty promising in that there isn’t a huge difference between these plant-based proteins and being based on animal proteins. There can be other logistical challenges around getting enough protein in as well as the amino acid profile and digestibility, which is usually where this argument is coming from.

It’s like, well, it’s hard to get enough. It’s not that good of a quality protein compared to animal sources a lot of the time. So that’s where it comes from. But again, looking at long term and acute research, it seems when we have a high enough protein intake, it doesn’t necessarily matter too much about this kind of difference in overall quality. Interestingly enough, we don’t have a ton of research on anything over like that 1.6 grams per kilo body weight.

Even like the small discrepancies that we do find in some of this research where animal proteins outperform the plant -based proteins, it could be potentially solved by just going a little bit higher. Personally, when I work with my plant -based clients, I will mostly go over that 1.6 gram per kilo body weight to make sure that we are overcoming these other variables. So more looking at 1.8 to 2.2 depending on the individual. I would just like to caveat here that because I do work in this space, I do know that there is more to think about. It is potentially harder to gain muscle mass and to optimise muscle growth just because of all these kinds of little bits and pieces that we do need to think about. The fact that it is a little bit harder to get to that high total protein intake on a day-to-day basis. So I never want to downplay the logistical challenges, but when we’re just looking at how they compare, they do seem very similar.

Aidan:

Particularly just cause like all of the problems that people point to get solved are high intake. Like if you, if people are just talking about the amino acid profile being lower in some amino acids, if you just have a really high intake, you end up with an abundance of all amino acids. If people are talking about bioavailability and digestibility, if you have a really high intake, even with slightly worse digestibility, you still get enough of everything. It’s just the logistical side of things. I just like addressing it because it’s like, it takes away the theory, the theoretical side about being like, these are terrible, quote on quote, and just being like, now we can just focus on the logistics and just being like, if we want to get in this route, how do we do it?

Leah:

There’s like a grain of truth to it, but we know that from a digestibility point of view, like typically plant -based proteins are 10 to 20% less digestible. So why don’t we just go 10 to 20% more protein intake in general, and then from an amino acid profile, just make sure we’re having a variety of sources.

Aidan:

The next myth is that low -fat dairy is worse because while they take out the fat, they add in heaps of sugar. I still hear this heaps to this day.

Leah:

It’s such an old one.

Aidan:

And like the funniest bit about it is you can just read a label. Like the funniest bit about it, and I’m truly trying to be non -judgmental when I say this, but like somebody saying this is saying it as a matter of fact, almost as if they’re trying to quote unquote educate in a way. But it’s like they haven’t read the label. Like, so like the short version is that sometimes they do that. Sometimes they do. But there’s multiple ways we can look at this. If we just started off by looking at milk and we compared full -cream milk to skim milk as an example, a cup of full-cream milk typically has 12 grams of sugar.

A cup of skim milk typically has 13 grams of sugar, but they haven’t added sugar to that skim milk. It’s just because if we’re comparing a cup versus a cup, it’s like 250 mL versus 250 mL. And if all they did was take out the fat, which is what they do, it would no longer be 250 mil. So it’s almost like they’ve had to pour a little bit more skim milk in there to make it a like-for-like comparison with 250 mL versus 250 mL. So with milk, on average, there are exceptions to this, but pretty much they’re not adding sugar to it.

With yoghurt, sometimes they do, sometimes they don’t. There are heaps of no-added-sugar or low-added-sugar yogurts on the market that are also low-fat. There are also heaps that do have added sugar. But it’s just a myth to say that like we’ve all low-fat dairy, they add heaps of sugar. You could debate other aspects of low-fat versus high-fat dairy, but I think that’s just one myth that I think makes sense to address.

Leah:

Love it. Next one is eat more fat to lose more fat, which again is one that has been around for a very long time. And I’m just gonna go through why we’re myth busting this. So this is based on the flawed logic that, but when we eat more fat, we burn more fat and therefore because we’re burning more fat, there is more fat loss taking place, which is an argument we often see in like the low carb keto spaces, particularly online. But realistically, your body will typically adjust

what it is burning as its primary fuel source, depending on what you are actually consuming the most. So if we have a really high carb availability, then your body is probably going to preface that as a predominant fuel source. And vice versa, if we have very low carb availability, but a high fat availability, that ratio will change to slightly favor fats. So yes, it does increase fat burning when we consume more fats. We could point to the research here as well though, but really, there is like a common sense thing to this.

So let’s say that you increase your dietary fat intake by a hundred grams a day. And that increases your fat oxidation rates, your fat burning rate by around 80 grams per day. But you can still see there’s like 20 grams of fat that is left over to be stored. That is a very simplified example, but it does highlight how fat oxidation in isolation is misleading. We care more about the balance of calories generally over the course of days, weeks and months, because it is the calories in versus calories out portion of this kind of general equation that really matters for fat loss.

It doesn’t matter if you are predominantly burning carbs or predominantly burning fat. It’s this overall energy balance that we care about. Though in the research, I think it’s just good to note that we do see low carb and low-fat diets both working well for fat loss when calories are matched just to just drive this point home.

Aidan:

The next one is that you can test for food intolerances with an IgG blood test. So IgG tests, they measure the levels of IgG antibodies in the blood, which produce part of the body’s immune response. These tests have been well and truly concluded to have a low level of accuracy for food intolerance testing. If you look at almost every reputable organisation in this space, like they do talk about this.

The presence of IgG antibodies is generally indicative of exposure to food, not intolerance. It’s easy to say this, but it’s also difficult to work or explain to somebody who has recently got a test, just because there’s two things like one, they’ve obviously paid for the test. Often people selling these tests are very charismatic as well. In addition to that, like a lot of people, their symptoms will often improve when they do action the test.

But that kind of makes sense. Like if IgG antibodies are generally indicative of exposure to these foods and somebody got the test because they’re experiencing a lot of symptoms, and then they cut out all the foods that they have been consuming regularly, it kind of makes sense that they are going to see some level of improvement in their symptoms. The reason why I care about this and I’m like, it’s worth kind of debunking this is just because it’s like, well, one, maybe we help some people before they get a test, but two, anyone who has got a test and has cut out a lot of these foods, even if there is improvements.

They have likely also cut a lot of foods that they didn’t need to. Having awareness of this basically means you can be less restricted with food and get the same results. I don’t want to make this because it’s a wrap fire. I don’t want to make this like a whole deal about how you do identify food intolerances. But at this stage, we don’t have anything that is as easy as this. I wish we did. I wish we had blood tests. I wish we had hair tests, DNA tests, etc, etc. I wish we had all of these kind of things that worked with a high level of accuracy. But we’re not at that point. At this stage, it’s really a systematic elimination diet and reintroduction. And then in those reintroduction phases, doing that in a systematic fashion where you identify, did this cause symptoms and identifying from there?

Leah:

The last one we’re going to cover today is you should or shouldn’t count collagen as part of your total protein intake. So there are definitely two sides to this. And I usually find that people like very, like very much will stand on one side or the other. But mostly I do see people saying we shouldn’t count collagen as part of our total protein intake. So the main complication here is that while collagen is a form of protein, it has a unique amino acid profile and it is not as good as at stimulating muscle protein synthesis as something like your whey based protein.

Its biological value is exceptionally low. We’ve covered this in other podcasts in how its amino acid profile can be unique for other things. But for things like muscle growth, it’s not a great quality protein just due to that amino acid profile. From our perspective, if someone has a relatively high protein intake, we could potentially count this towards their protein intake because it’s like, well, you already have an abundance of different amino acids, different essential amino acids.

So assuming that protein intake is high enough to overcome this little bit of an issue and collagen isn’t a huge part of that total protein intake, then we probably would be fine with counting it towards that. But on the flip side, if someone had a low protein intake and maybe they’re on like the lower range of that rough guide of 1.6 to 2.2 grams per kilo body weight, it could be useful to maybe not count collagen towards that intake and just have it on top.

so that we know that we’re still optimising things like muscle protein synthesis and recovery and muscle building if that is the predominant goal. So if you’re someone who has 30 grams of collagen protein per day, I would just look at your overall total protein intake, and see where it is within that range. If it’s on the lower end, okay, maybe don’t count that. But if you’re getting just a really good amount of protein, it doesn’t matter too much and I would count it towards it.

Aidan:

Perfect. If anyone has any feedback on whether they like this style of episode or whether they prefer us just deep diving on one topic, let me know. Send me a DM on Instagram. I check our stats. We do get slightly more views on episodes like this where we cover a bunch of stuff, but I just want to hear from you guys and see if there’s anything that you personally prefer. But apart from that, that has been episode 156 of the Ideal Nutrition podcast. As always, if you could please leave a rating and review, that massively helps us and would be massively appreciated.