Mini Mikkipedia - Considerations for the vegetarian athlete
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Hey everyone, it's Mikki here. You're listening to Mini Mikkipedia on a Monday. And today I'm gonna chat about the vegetarian athlete because there are certain nutrition considerations which I feel could warrant a little bit more attention beyond just the micronutrients and macronutrients we know to be of concern. So I'm gonna run through them as I see it and then also have a chat about blood biomarkers.
just at the end. And I will preface this by saying that whilst of course I have an omnivore diet, I work with a number of athletes and individuals looking to optimize their vegetarian approach. These are conversations that I'll have in my clinic at least every couple of weeks because there is a way to do it properly so you're not going to be at risk of losing muscle mass or impacting negatively on recovery.
This is particularly for people with high energy requirements and a lot of teenagers would fall into this and particularly teenage girls who may turn vegetarian because of a moral stance or they have it in their head that this is going to help with their body composition or whatever it is. Yet often those health conscious ones take it just a little bit further than what ideally it would be taken.
And calories are of a concern in this space because teenagers particularly have high energy requirements just through the fact that they're growing plus their sport and of course to fill their brain for school etc. And there are just periods of the day where they just can't eat all day long, right? Not that you would necessarily want them to. And vegetarian based diets can be challenging in that getting quality calories.
can be limited because there is an increased fiber intake. From people who follow a vegetarian diet, which has a lot of beans and vegetables added, getting the calorie requirements in quite a high volume diet can be tricky. So, you know, if I look at the literature around this area, on balance for adults at least,
The difference in energy intake between omnivores and vegetarians might be only about 5%, which isn't actually a major in the big scheme of things. Someone may easily maintain their weight in that space, but it's just those higher energy requirements from a vegetarian athlete. And another person I would, or avatar if you like, that I would put into this camp would be potentially a male who is doing endurance-based sport, who has gone vegetarian and isn't
calories or supplementing. So they're just sort of loading up a lot on beans and rice and potatoes and and hey maybe cheese and stuff like that but find that they're actually losing weight but importantly they're unable to recover as well. So I think calories is or can be a major consideration but then of course to turn that on its head sometimes people can absolutely overdo calories particularly if they're chasing something like protein and protein which
It's more difficult to get in a vegetarian diet. And you do have to consume almost several hundred calories more to get the same amount of protein that you would otherwise find in a steak. If this is the case for some people, then their vegetarian approach by dropping out meat can in fact increase the calories and make it more challenging for them to maintain a body composition that aids performance and also aids health.
So I think that's also really worth considering too. And of course from the macronutrients, protein is the major one of consideration. And protein quality is a term which we refer to here. So it encompasses a protein's sources of amino acid composition, its digestibility, and subsequent bioavailability of specific amino acids. And also of course that metabolic fate of those amino acids.
Such factors are affected by the specific protein source, whether it's consumed as isolated protein such as you'd find in a protein powder or as a protein-rich whole food, and whether that protein source is consumed alongside other foods in a meal. Irrespective, the quality of a protein source has reliably been shown to play an important role in determining the magnitude of post-exercise muscle protein synthesis response. And that response is… responsible.
for aiding recovery. So milk, egg and meat derived proteins all stimulate robust post-exercise NPS response and this is attributed to their high essential amino acid content, particularly leucine, a lack of any notable amino acid deficiencies, rapid digestibility, and a high total digestibility and absorbability and therefore more availability in circulation.
So that is that they're just more bioavailable. And this has been observed in a number of studies using milk, using eggs, using ground beef and beefsteak. So we're quite confident that if you have these foods, then you're gonna be okay, particularly if they're in a certain amount, right? In contrast, there are in fact fewer studies looking at post-exercise MPS response following the ingestion of non-aminoderived proteins.
Nevertheless, there is a widely held view that these non-animal proteins are inferior with respect to their capacity to stimulate that NPS rate compared with animal proteins. The lower anabolic potential of these proteins is thought to be attributed to a few factors. So, the presence of non-protein constituents and anti-nutritional factors are thought to slow and reduce the digestion and absorption of protein, meaning that a lower
proportion of ingested amino acids become available in circulation after a meal. So they're just not there to help with that muscle protein synthesis. However, if you were eating these amino acids in their purified form, so isolated from these other food constituents, it does help that digestibility. So the digestibility or the lower digestibility is attributed to the fact that they are in a whole food and a food matrix.
So once you strip them out and have it in, say, a protein powder form, it's actually much better. Despite that though, these plant sources frequently have lower total essential amino acid contents, and leucine, methionine, and or lysine in particular are amino acids which are suggested to provide limitations to that muscle protein synthesis response, either at the molecular signaling or substrate availability level. And this is
true when we're looking at studies investigating wheat or soy protein compared to their animal-based sources. However, interestingly, there have been studies recently demonstrating that getting a good bolus ingestion of mycoprotein, which is a fungal-derived protein-rich source, and I believe that if you eat something like corn, that Q-U-O-R-N product, that's made of mycoprotein,
This does result in a greater stimulation of NPS compared with a leucine-matched bolus of milk protein. So non-animal protein sources aren't necessarily less anabolic, but require consideration on a case-by-case basis. So you can't just blanketly say, that's gonna be lower. An emerging theme is that the differences between animal and plant-based protein sources are absent when we have higher doses of protein.
So, and I talked to Don Layman about this in an upcoming episode in that you will need to, as a plant-based or a vegetarian, if that's what you're getting a lot of your protein from, you need to eat more of that protein source to get a similar muscle protein synthesis response. Whereas in certain situations where 25 grams of animal-based protein is enough to hit that NPS, you might be looking at about 40 grams of a plant-based protein to get a similar response.
Blending plant protein sources is suggested as a way to get rid of these essential amino S deficiencies. So for example, if you find a protein powder that has both brown rice, which is low in lysine and high in methionine, and it's blended with pea, which is low in methionine and high in lysine, the combination of these two sources could result in a more complete EA profile. And when I started out in nutrition, it was often
recommended that vegetarians at each meal ensure they have this sort of complete protein from their different sources. Albeit nowadays, it's sort of accepted that as long as you've got these different protein sources across the course of a day, in an amount which when digested will stimulate enough muscle protein synthesis, you're gonna be okay. And another suggested method is to improve the anabolic potential of plant proteins
to fortify them with a given protein with amino acids. Leucine is considered the key amino acid for activating that molecular signaling that underpins this increase in muscle protein synthesis. Implant proteins are often low in leucine. So it is thought that additional leucine might potentiate this anabolic response. And in some studies we see this to be true, but in others it fails to actually make a difference. So.
It is sort of concluded that more research is probably needed to establish whether amino acid fortification is effective or necessary. And upon saying that, this is a practical clinical recommendation that I would make to my clients who are vegetarian and are unable to eat a higher quantity of vegetarian protein in their meal, or the calorie budget doesn't allow for it. So we add in an essential amino acid source to boost that leucine content.
Now, when it comes to carbs, really the major thing to consider here is the bulk of the diet. So one, a higher carb intake for a vegetarian is almost par for the course. And you have to weigh that up with the caloric requirements and the nutritional goals and body composition goals, obviously. Many of the sources of protein which vegetarian athletes rely on are actually better sources of carbohydrate such as beans and legumes.
and the higher fiber content, as I mentioned at the sort of start of this, can make it difficult to optimize carbohydrate for some individuals with higher energy requirements. So we just have to carefully consider training needs, body composition, and of course personal preferences when we are looking at the carbohydrate intake of a vegetarian athlete. Now another nutrient
Now the shift away from the macros is creatine, and this may be particularly important for vegan athletes. So about 1-2% of the body's creatine pool is excreted per day as creatinine. Therefore, for the average 70kg male, I'm not sure why we always have just an average 70kg, I don't know that that is average, but anyway, the daily requirement for creatine is around 2g, 50% of which is obtained through diet.
However, creatine is only available in animal products, primarily meat and, albeit less so, from some dairy products. So due to the lack of creatine in the vegan diet, both vegan and vegetarian individuals have lower plasma levels and intramuscular creatine compared with their omnivore counterparts. So given that creatine supplementation can have profound effects on parameters of adaptation and performance, it does seem logical that vegans
may experience a decrement in this regard and may wish to consider supplementing with creatine, particularly as it has been previously demonstrated that creatine supplementation has resulted in greater increases in creatine stores and lean mass in vegetarians compared with omnivores. So there's more room for improvement there. Upon saying that, I would just get all my athletes to really supplement with creatine if I'm honest. We see really good performance gains.
and if we're looking at high exercise intensities and or looking to maximize hypertrophic or strength adaptation then taking creatine in the levels of about three to five grams a day will slowly but surely saturate those cells so I would definitely look at that as a supplement. Now one that is not often considered is carnitine so this is another zoo nutrient which is found in animal protein
And irrespective of the lack of clarity over whether or not there's a deficiency, the ability of carnitine supplementation to augment performance does make it a worthwhile consideration. One practical consideration does merit discussion. And this is for carnitine supplementation to successfully increase muscle carnitine stores. It must be co-ingested with carbohydrate to ensure an increasing and circulating insulin concentrations.
So that could have implications for energy balance. Now, carnitine is responsible for shuttling sort of fat across the cell membrane. And this is one of the things that we want it to do. And so increase the body's ability to utilize fat as a fuel source. And indeed, even omnivore athletes could benefit from an increase in L-carnitine. And I know Dom Dagostino, who follows a low carb slash ketogenic approach,
has three to four grams of L-Carnitine every day, despite the fact he has a ton of foods that would otherwise contain it. Looking at studies in this area, a two gram a day carnitine supplementation for 12 weeks has been shown to successfully increase muscle carnitine stores in vegetarian individuals, and there haven't really been any adverse effects or events being reported. And it's worth noting that probably as in many areas, more
Studies will likely need to be done in this area. Carnitine is another one. It's a dipeptide found in high concentrations within skeletal muscle where it acts as a buffering agent. The contingency of the pathway that utilizes and helps with carnitine action includes histidine and B-alanine or beta-alanine. Histidine is abundant within skeletal muscle, but beta-alanine is found in relatively low concentrations.
So therefore studies investigate whether beta-alanine supplementation is capable of increasing muscle carnosine content and may improve high intensity exercise performance. And what I will say is there is a body of literature looking at beta-alanine and it appears to be one of the, it's one of the most widely studied, it is safe, and it appears to be an ergogenic aid. So...
I wouldn't have any hesitation really in recommending someone give it a go and see how that goes. And it's primarily sort of valuable in athletes competing in these high intensity, moderate duration exercises like swimming or rowing or something like that. Beta-alanine is exclusively found in meat and fish and therefore completely absent from the vegetarian or vegan diet. So because there is such that
such a tight link between beta-alanine and muscle carnosine, it's no surprise that vegetarians do have lower muscle carnosine content. And we don't know though that this is actually associated in impairments in exercise performance, but given that increasing muscle carnosine content can improve exercise performance, it's plausible that reduced muscle carnosine content can impair performance. So you would want to be taking beta-alanine.
in daily doses of about 2.4 grams during the first four days, and then 3.6 grams during the subsequent four days, and then about 4.8 grams a day thereafter. And this is a strategy that has been used in trained individuals. It is also advised to split these into smaller doses where possible because this may prevent symptoms of sort of pins and needles in the skin, albeit...
who doesn't mind a little bit of pins and needles to fire them up, right? And a lot of the pre-workouts that I've used have beta-alanine in amounts of about 1.6 grams and you get a good old tingle before you get out and do a hard out run. Maybe it's psychological, but it tends to work. Now, of course, the micronutrients, which we are undoubtedly familiar with. And this is where blood tests sort of can come in. And I always recommend vegetarian and vegan athletes get blood biomarkers.
Iron is of course one of the first ones, but you don't just wanna test ferritin because ferritin is a marker of not just iron stores, but also of inflammation. And so if you regularly train hard, your ferritin is likely to have increased to reflect a hard session. So you want to get your both ferritin and a full iron panel measured at the doctors.
or at the lab tests to determine sort of your full iron status with that. And ideally you would get it done after an overnight fast of about nine to 10 hours and you'd be fully recovered. And another test to get done is of course, vitamin B12. It's related to nervous system functioning, DNA synthesis, homocysteine metabolism and does have indirect links to energy metabolism too. And it's found almost exclusively in milk.
dairy, eggs and meat. And even though you may find naturally occurring forms of B12 in some plant foods, they're not in forms that we can actually digest and absorb. So it doesn't matter what's in the food, what matters is what you can absorb. So definitely check your vitamin B12 and get a blood test for that. And have a think about the optimal versus normal reference ranges, which...
If I haven't done a mini-micropedia on, I'm definitely gonna do one on that soon. And what I will actually also note with regards to iron is that there are plenty of foods that contain iron, but it's much less available because it's a non-heme iron. So it doesn't come from a form which is bioavailable for us. And the differences from like two, like less bioavailable, even from two to 20%, then heme iron, which is 15 to 35%.
But even in a mixed diet, we don't get a ton of iron. This may not be the case for a male vegan athlete. They may well be able to maintain a sufficient iron status. But again, you wanna check ferritin and a full iron panel. So you don't falsely think that your iron is sweet just because your ferritin is raised. And another tip on that is if you have in the past been deficient in iron, then you do wanna get regular testing.
at least once a quarter depending on the state of sufficiency or deficiency to ensure that you're able to maintain iron. And then if you aren't, you really do want to look a little deeper. Calcium is another one and you know calcium of course we know is involved with bone formation and bone health and 99% of our calcium is stored in our bones and our teeth and the remaining calcium is stored in the muscle, the bloodstream and an extracellular fluid.
Obviously if an athlete eats enough dairy, then that's going to account for about 70% of their total calcium intake. And calcium from other sources like Chinese cabbage, kale, and soybean may well not be as bioavailable just because of other calcium-binding food components such as phytic acid, oxalic acid, and cellulose. And studies that have looked at omnivore versus vegan diets have found that vegans are more
at risk of a bone fracture compared to their omni-vore counterparts, so this is another reason why this is worth considering. Calcium homeostasis isn't influenced by exercise. There is potentially an acute decline in plasma calcium concentrations, but that is transient, as prolonged periods of training don't seem to modulate these plasma calcium levels. They're not at risk of disturbed calcium homeostasis.
but special attention should be paid to people who have not just low calcium, but potentially low energy as well, or higher metabolic output, because there is this association between low calcium and menstrual dysfunction, low energy availability, and decreased bone mineral density. And it's advised that vegan athletes do monitor their calcium status and consume calcium-fortified foods or calcium-rich food products. And there are...
calcium supplements available in two forms, calcium bicarbonate and calcium citrate, which have a similar intestinal absorbability. And I think it is also worth mentioning that we often hone in on calcium as a supplement necessary for bone health, and of course it is, but there are other things which are just as important, such as adequate calories, sufficient protein, resistance training, all of these things.
And it is worth noting as well as if you've got say a teenager who does a lot of non weight bearing activity, then definitely looking at their bone density is worthwhile because I've dealt with athletes who are in their sort of early twenties with low bone mineral density because of their gears sat on a bike or in a pool or in a kayak. And finally, you would always just want to check out what's going on with vitamin D because
it's still going to be lower from the diet in someone who is exclusively plant-based compared to an omnivore. And I believe even looking at the literature, you've got levels of intake per day in the UK showed that vegans had 0.7 micrograms compared to an intake of 3.1 micrograms in omnivores. And in addition, the serum levels reflected that lower.
dietary intake and they were maybe about 20 millimoles or nanomoles, I'm sorry, lower in the vegan athletes. So having said that, vitamin D through dietary sources is actually a small amount of the vitamin D that we get. So we would get dietary derived vitamin D2 in plants, mushrooms and yeast, whereas vitamin D3 is in those animal-based foods. And we need to sort of convert that D2 into D3.
But the sunlight is where you're gonna get most bang for your buck with having higher levels of vitamin D. So we wanna make sure that this, that we are on top of our vitamin D as athletes, both vegan and omnivore alike, because you can have inadequate bone mineralization, you can have soft bones, osteomalacia, and you can also have immune function issues, thyroid or hormone issues.
mood issues. So there's a lot that can go wrong when you're low vitamin D. So I would definitely recommend testing vitamin D, even though in New Zealand that's likely a user pays test, and then supplementing accordingly using a vitamin D3 product and ensuring that your serum or your blood marker for vitamin D is up at around at least 80 if not 100 nanomoles per liter. All right then, so those are the major considerations with
vegetarian athletes and it's probably more than what most people consider which is why I thought it warranted a little bit of a longer discussion on it. We know about protein, we know about iron, probably most of us know a little bit more about vitamin D but there is the carnitine, the creatine, the carnosine, those zoo nutrients and also of course calcium as well and the calorie issue. So hopefully you've...
got something out of this mini micropedia that you can pass on to your vegetarian counterparts. And if you do, then absolutely send them this episode. All right, team, thanks for listening. You can catch me over on threads, Instagram, and Twitter, or X, @mikkiwilliden. Head to Facebook @mikkiwillidenNutrition, or head to my website, mikkiwilliden.com, where you can send an inquiry through my website. You guys have a great week.