Blog Post

The Game Changers: A Dietitian’s Review

The Game Changers Netflix Documentary

When The Game Changers documentary came out on Netflix, I felt I had to watch it. It was almost a job requirement for me, since not only am I a dietitian, I’m also a sports dietitian specialising in strength athletes and I have a bit of a presence on Instagram. This meant that I had a crazy number of questions coming in about the documentary.

Nutrition documentaries typically have quite a lot of bias and do not represent the totality of the evidence well. This is a common theme” because honestly, the fundamentals of nutrition typically are not that interesting for the average person.

To really bring in an audience they need to make bold claims.

Nobody is interested in hearing what they have heard before. People want new and different. They want something that is a bit of a “secret” that can potentially help them get abnormal results.

Since I’ve waited so long to write about this, I’ve had time to watch it multiple times as well as listen to the debates on the Joe Rogan Podcast, in addition to reading quite a lot of the other reviews of The Game Changers as well.

I am not so much writing this because I feel like I have more value to add in comparison to what has been said so far. There have been some brilliant reviews done already. I am more writing this to add my own thoughts in a more comprehensive manner so that when people ask me for my thoughts, I have something to direct them to.

James Wilks

James Wilks

I am going to start by discussing James Wilks since the documentary is built around his journey of discovering how plant-based diets could be beneficial for him as an athlete, as well as how it could benefit other athletes or those looking to improve their health.

Even that aspect alone is worthwhile mentioning. It is a crucial part of why the documentary got so many views.

People like stories. Stories are an effective way to spread information to the masses in a more effective way than just stating facts.

In addition to that, people typically DO NOT like to be spoken down to. They do not like to just listen to an expert sharing their expertise.

Instead, most people prefer to go on a journey with somebody learning alongside them. James frames himself as a “meat-eater” near the start of the film, which helps people relate to him.

This is also why people who are not experts in the nutrition field often have so much success inin selling nutrition books or products.

For example, Michael Mosely is a journalist/doctor. But he has one of the highest-selling nutrition books, which is based on the 5:2 diet. In this book, he mentions how he was “surprised to learn how a glass of skim milk has 10g of protein.”

That example is crazy since that is a relatively basic nutrition fact. Yet the guy claiming to have just learnt that basic fact, is the same guy who was writing a best-seller on the topic not long after.

Do you want to learn from somebody who has only recently learned a basic fact in an area but is now framing themselves as an expert? Or would you rather learn from somebody who has been an expert for a longer period and has dedicated their lives to a topic?

When it is framed like that, most people THINK they want the latter. But in reality, due to human psychology, most people find it easier to be open to learning when they feel like they are on a journey with the person they are learning from.

The amount of times James Wilks says “I was surprised to learn” in this documentary is eerily similar to that example.

It is also crazy because James Wilks actually seems like a smart guy. Although he mentions how he spent 10,000 hours reading studies, to position himself as worth listening to, he then goes on to undersell how smart he is for a lot of the film.

It was not until he was on The Joe Rogan Podcast that I appreciated his intelligence and ability to recall information. There were so many times a key point would come up in the debate and I would be hoping Chris Kresser (who to be fair, was not the ideal candidate to be on the other side) would bring up certain studies I was familiar with.

James Wilks, Chris Kresser and Joe Rogan

And almost every time these studies were brought up, James was familiar with the study and knew the numbers better than Chris did. This does not mean his interpretation was always right, but it is a massive sign that he is great at retaining knowledge and has spent a LOT of time looking at the research.

I know he had a team around him that helped him prepare, but he clearly has still put in a lot of work.

So regardless of bias, nobody can doubt that he has done his homework and is an intelligent guy.

Plant-Based Diets and Injury Recovery

The catalyst for James going down this rabbit-hole of nutrition research was an injury. To be more specific he had torn ligaments in his knee.

This led to him recognising a few key aspects of nutrition for injury prevention and recovery, such as focusing on an anti-inflammatory style of eating.

Increasing your intake of fruits, vegetables, wholegrains, and legumes absolutely can help with this and I would encourage this for the majority of people.

Dietary patterns that are high in these types of foods are often linked with reduced inflammation in the research, regardless of what some people might say.

Omega 3 fatty acids are also linked with injury recovery and reduced inflammation as well. While the types of omega 3 in plant-based sources is different to what you would get from fish, this effect still appears to be present if sufficient amounts are consumed.

One aspect that I think is worth mentioning though is the potential impact of collagen/gelatin supplementation on injury recovery.

Collagen Supplementation for Rehab

Collagen can only be found from animal sources and there is not yet a vegan equivalent. Agar is often used as a vegan substitute, but it does not contain the same nutritional profile or have the same effects.

Although it is early days, collagen supplementation looks promising for musculoskeletal injuries when used appropriately. This is also being trialled in athletes with similar injuries to what James sustained, with what looks like great success.

Bone broth is a food first alternative to supplementation, but it does not look like it consistently provides sufficient collagen precursors in a reliable enough fashion to optimise collagen synthesis.

With a lot of points I will make later in this article, you can make substitutes on a strict plant-based diet to prevent any adverse effects. But in this case, it is a rare exception where it looks like that will not work.

Collagen and gelatin have quite unique amino acid profiles where they are high in glycine, lysine and arginine. This makes them relatively poor for promoting muscle protein synthesis in comparison to other protein sources.

But it looks like consuming other protein sources might not be as effective for promoting collagen synthesis. There is currently only one study on the topic though so this might change in the future.

This study compared casein protein to collagen and showed that casein protein did not increase collagen synthesis.

Casein vs collagen for collagen synthesis
Image via @nutritiontactics on Instagram

The research so far seems to indicate that consuming a sufficient intake of amino acids does not seem to provide the same outcome for collagen synthesis. Therefore, this is a rare circumstance where following a strictly plant-based diet might not allow you to optimise your nutrition for your needs.

EDIT: An idea that I later had following the writing of this blog post – potentially you could supplement the individual amino acids that collagen is high in (proline, glycine, lysine and arginine) alongside vitamin C and get similar results. I have not heard of any plant-based athletes doing this, but it is something I would consider to solve this problem.

Protein for Energy

One of the weirdest points from the documentary is when they introduce this concept of athletes thinking of protein as an energy source. I believe it was Dr James Loomis who brought up this idea.

Frankly, I do not believe many athletes believe that protein is their bodies best energy source for training and performance.

While most athletes do not fully understand the systems involved, I believe that carbohydrates have been so heavily emphasised for this purpose, that athletes understand that carbohydrates are the bodies preferred source of energy during exercise.

But busting this myth (whether it is a relevant myth or not) helps to frame their argument against higher protein intakes.

To make matters worse though, they then go on to say that overconsumption of protein instead of carbohydrates leads to glycogen depletion, fatigue and loss of stamina.

Gluconeogensis Diagram

This is quite misleading since it ignores the fact that protein can comfortably be converted to glucose through gluconeogenesis.

While carbohydrate may be slightly easier to utilise as fuel and prevent glycogen depletion, protein also aids in this. Consuming protein does not “lead to glycogen depletion.” In fact, adding protein to a carbohydrate supplement aids glycogen replenishment significantly more than carbohydrate alone does.

Protein Needs for Muscle Growth

As I said earlier, I respect the knowledge of James Wilks. He knows the ins and outs of protein needs for athletes. He also has a solid team around him that can help put this into practice as well.

In the film, he quoted studies regarding how much protein athletes need.

One study that was discussed separately on the Joe Rogan podcast was this study by Alan Aragon and Brad Schoenfeld.

This study indicates that “that to maximize anabolism one should consume protein at a target intake of 0.4 g/kg/meal across a minimum of four meals in order to reach a minimum of 1.6 g/kg/day. Using the upper daily intake of 2.2 g/kg/day reported in the literature spread out over the same four meals would necessitate a maximum of 0.55 g/kg/meal.”

Optimising Protein Intake for muscle growth

He also mentioned (rightly so) that these numbers are likely higher than what most athletes need to be consuming throughout their careers depending on their needs. This is more of a target for maximising muscle anabolism.

The number he quotes in the film is 1-2g/kg/day, which is a broad range, based on the different needs of athletes. I mostly agree with this as a general statement as well.

You 100% can meet these needs from a vegan or plant-based diet.

I do feel that he underplayed how well planned out your diet may need to be to reach these targets though.

He pointed out that his diet was already comfortably meeting this target. This kind of made it seem like you can hit this target without trying.

But a large survey of vegans highlighted that their average protein intake was 83g/day. Obviously, this will vary from person to person, but to me, it is one of many signs that it takes effort to reach a higher protein target.

In addition to this, the higher your protein needs are in relation to your calorie needs, the more difficult this gets, as I will discuss later.

This is because calories are literally made up of macronutrients.

Protein = 4kcal/g

Carbs = 4kcal/g

Fat = 9kcal/g

Most plant-based foods either have more carbohydrates or fats than protein. Therefore, on a restricted energy budget it can be difficult to meet protein needs without planning it out.

Beyond that, while the quality of the amino acid profile of the protein sources does not appear to matter as much when total protein needs are met, it appears to matter more for sub-optimal intakes.

Leucine is an amino acid particularly crucial for maximising muscle protein synthesis and most plant-based protein sources are relatively low in leucine in comparison to their animal counterparts. This is also part of the argument as to why people following plant-based diets might require slightly more total protein per meal/day to maximise muscle protein synthesis.

Protein Efficiency

Beef vs peanut butter sandwich protein comparison

One of the claims in the film that stirred up some controversy is that James Wilks once again points out how he was surprised to learn that 1 cup of lentils or a peanut butter sandwich has as much protein as 3 eggs or 3oz (~85g) of steak.

While an 85g steak is very small in comparison to what the average person consumes, these numbers are not overtly inaccurate.

In the heat of the debate on The Joe Rogan podcast, James Wilks appeared to come out on top with this point.

Unfortunately, it was quite frustrating to listen to, because they got the numbers wrong. They had doubled the amount of protein in bread (using the per serve numbers for per slice) while doing the maths, which warped the point.

The picture I have included above comparing 85g of lean beef to the peanut butter sandwich is not meant to directly compare the point that was being made. I have specifically chosen lean beef, which is slightly higher in protein and significantly lower in calories than a higher fat alternative.

I also have no qualms with using a lean cut of meat for this example, since in the film they made an effort to try paint ALL meat in a negative light, not just higher fat versions.

But it shows the point I am making about calories per gram of protein. If somebody was trying to get leaner while maintaining as much muscle mass as possible, they could find it difficult to stay in a calorie deficit while hitting their protein target.

It is still possible to do on a plant-based diet, it just requires planning. I am solely highlighting this since the film indirectly made it look quite easy to reach protein needs.

Getting Stage Lean as a Bodybuilder on a Plant-Based Diet

The Game Changers Bodybuilder

At one point, a bodybuilder is featured saying how he thought he would not be able to be competitive on stage as a plant-based bodybuilder but says it has not negatively affected him.

While I truly believe that once again, you can set up your diet optimally as a plant-based bodybuilder, this is just another example of anecdotal evidence.

There are literally evidence-based recommendations for nutrition for contest preparation that we can utilise that would be far more valuable than anecdotes.

The protein recommendation during contest preparation is 2.3-3.1g/kg/day based on fat-free mass, (instead of total body weight – which is what the other recommendations thus far have been based on). Credit to James once again for being aware of these recommendations and knowing them well while discussing them on the podcast.

But I wanted to highlight that meeting that high of a protein target is super hard while in a calorie deficit. And people going through prep are typically in a calorie deficit since they are dropping body fat.

It is hard to achieve this protein target in a calorie deficit on an omnivorous diet, let alone a plant-based diet.

As somebody who has worked with a lot of athletes and made meal plans for plant-based competitors, I can confirm that without protein supplementation, it is incredibly difficult to reach these targets without exceeding the calorie targets.

Protein Efficiency Chart

Another aspect that frustrated me is how this bodybuilder mentioned how he was backstage eating carbs while all the other bodybuilders “haven’t touched a carb in weeks.”

Honestly, this is ridiculous, especially if it were true. Firstly, throughout prep, most bodybuilders do not go low-carb. They go lower carb than they did in the off-season, but typically they do not drop down to a minimal intake.

But the part that frustrated me is that bodybuilders SHOULD carb-up leading into a show. It increases their glycogen stores, which also increases intramuscular water content. This makes them look more muscular and vascular on stage, which increases their odds of winning.

This is a common practice. Anybody not doing this is undertaking a sub-optimal nutritional strategy. This is something I’m going to talk about later. Going from a sub-optimal diet to a more optimised diet is going to be beneficial regardless of whether it is omnivorous or plant-based.

Patrik Baboumian

Patrik Baboumian

Moving onto another strength sport, this documentary features vegan Strongman Competitor Patrik Baboumian.

His sections highlight how well-crafted this documentary is from a theatrical perspective. There is a lot of footage of him performing feats of strength.

This is where the value of having people such as James Cameron and Louie Psihoyos involved in the film really comes into play. By making the documentary so engaging, it really increased how far the message was spread.

On that topic, there are a lot of thought-provoking one-liners that are used. Without context, they seem compelling.

One example of this is when Patric says “How can you get as strong as an Ox without eating meat? And I say ‘have you ever seen an ox eat meat?’”

Another one-liner used by somebody else later in the film is “look at a Gorilla. It will F you up in a few seconds. What does a Gorilla eat?”

While these sound clever, how are they relevant to humans and muscle mass? We have sooooo much research. Disregarding that based on a one-liner would be silly. 

Onto the important point though. Patrik claimed he gained 25kg after switching to a vegan diet and then also went on to break the record on the yoke carry with 1230lbs for 10 metres in 2015. He previously held the record at 1213lbs from 2013.

The first thing I wanted to point out is that Patrik competed in a non-drug-tested sport. This is a sport where people are dedicating their lives to winning, which means there are athletes who are very likely to be taking performance-enhancing drugs.

Since it is not drug tested and it is fair game, it is not considered cheating to use steroids.

I cannot directly say that Patrik was taking steroids.

But if you put two and two together and understand that steroids make you stronger and more muscular, and he held a world record in a federation where people can freely use steroids without any risk of getting caught, it could be fair to assume that he also was likely taking steroids.

One thing the film did not highlight is that during this time, Patrik was consuming 4 protein shakes per day as part of a diet that contained a total of 410g protein. That is a lot of protein.

According to this article, his diet looked like:

Meal 1: Shake – 80 grams of protein, 5 grams Creatine, 3 grams Beta-Alanine

Meal 2 (post-workout):  Smoothie – Black currants, frozen mixed fruit, 80 grams of protein, glutamine, beta-alanine, 5 grams of creatine, dried greens, turmeric, cinnamon, 5-10 grams BCAA’s, orange and mango juice, and water.

Meal 3: Vegan sausages, falafel, fries and grilled veggies

Meal 4: Protein shake – 50 grams of protein, 5 grams of fat

Meal 5: Veggies, tofu, potatoes

Meal 6: Peanuts – 60 grams of protein, 20 grams of carbs, and 90 grams of fat AND a protein smoothie – 50 grams of protein

As you can see, he was supplementing quite heavily to meet his protein needs. In my opinion, this is probably a good idea, since it makes it much easier to meet needs. But this aspect was not really discussed by the film, since it does not really support the case that was being built.

Also, it is worth noting that since that record was made, both Brian Shaw and Hafthr Bjornson have carried 1565lbs in 2017, which is 335lbs more.

That’s a massive increase and it is worth documenting that both of these athletes consume massive amounts of meat and have also utilised The Vertical Diet, which features large amounts of red meat.

The Vertical Diet

If we are looking at anecdotal evidence, it would be hard to ignore that the majority of successful strongman competitors consume large amounts of meat. There are exceptions, but they are few and far between.

You could say that well-executed plant-based diet could be just as good for performance, but to argue that it is superior would be a big stretch that is not supported by the evidence.

Thoughts on Supplementation

When reading another review on the Game Changers, I saw somebody write something along the lines of “I guess you can be as strong as an Ox without eating meat, but I bet that they also do not need 4 protein shakes a day either” which got my interest.

I am a “food first” kind of guy. But I am also all for supplementation when it is beneficial.

And one great point I heard James Wilks mention is that it is illogical to slam vegan diets based on the fact they often require supplementation.

People often point to how B12 supplementation is necessary (as I will discuss later) and how that is a clear sign that we should not follow a vegan diet.

But the point James made was that almost every athlete is using supplements regardless. A large percentage of omnivorous athletes also use some form of protein supplementation.

To highlight that because vegan athletes are also using supplements as a “clear sign that they are worried their diet is inadequate” is a bit silly in my opinion. Athletes use supplements regardless.

Conor McGregor vs Nate Diaz

Conor McGregor vs Nate Diaz

Moving on to some more anecdotal evidence. The documentary features a fight between Conor McGregor and Nate Diaz and insinuates that Nate wins because of his superior plant-based diet.

This is awesome because it highlights that you can perform well on a plant-based diet.

But once again it is a bit of a misleading point that is just another example of confirmation bias.

Firstly, we cannot assume that Conor was following an optimal diet. In addition to this, it is also insinuated that Nate was following a strictly plant-based diet, which is inaccurate since he has mentioned he was having eggs and fish occasionally.

I am not an expert when it comes to MMA, but I am aware that Conor went up 2 weight classes in a short time span for this fight.

That puts him at a massive disadvantage since you cannot gain muscle that quickly. Plus almost every fighter does a water cut in the lead up to their fights to give them a further advantage.

Diaz was significantly heavier on fight day and in much better condition for the fight. From what I have read, Nate’s fighting style also put him at an advantage as well.

These are all factors that are unrelated to the dietary pattern they followed.

In addition to this, Nate has also lost quite a number of fights as well. There is more to this than just diet. To imply that Nate beat Conor in large part due to his plant-based diet is a bit silly, since that ignores all of Nate’s previous losses while following a similar diet.

In addition to this, they had a rematch that Conor McGregor won. This is not mentioned in the film since it does not fit the agenda.

Conor McGregor vs Nate Diaz Fight

Documentaries are made to be compelling. They are designed to inspire change. Adding in aspects such as what I have just mentioned above discredits the nature of the documentary, which is why they could not be added in.

I am only mentioning them to remind people to think about a topic from multiple angles.

Beetroot Juice and Endothelial Function

Beetroot Juice in Glass

Endothelial function is discussed quite a bit and it looks like a compelling argument for a plant-based diet.

Firstly, you can get those benefits from consuming more plants in general, so it is a good message to send.

But the big thing I care about is how endothelial function and improved vasodilation actually carries over into improved performance.

The documentary discusses how beetroot juice allows people to cycle for 22% longer on a time to exhaustion test. It also mentions how in one study, it allowed participants to bench press 19% more total weight.

Those numbers are insane. Personally, while I may or may not have a bias, I care about performance above all else.

I am an athlete myself, and I work with athletes who are at a much higher level than myself.

As somebody who works with a lot of high-level powerlifters, if I found something that could add 19% to somebody’s bench press, do you think I would not utilise it? Or do you think I am hiding it due to some kind of conspiracy?

Hell no. I would share that with the world. I would get all of my clients on it since my goal is to improve their performance.

To quote Louise Burke, who is a legend in the sports nutrition world, “my job is in optimising elite performance. If there is a diet that is going to make athletes faster and perform better, I am going to want to know about it and implement it.”

This applies to plant-based diets and also this beetroot juice example.

If something looks too good to be true, it probably is.

Firstly, the study referenced did NOT increase the weight lifted by 19%, which was the quote from the documentary. I have double-checked that to confirm I heard it accurately. What actually happened was the participants did 60% of their 1RM to failure over multiple sets and were able to get more reps.

60kg bench press

So across the 3 sets, we are talking sets of 10-20 reps, with more in the earlier sets and less towards the end. The study also only included 12 people, which is relatively normal for a nutrition study, but worth mentioning for something like this since there are a lot of variables involved.

Beetroot Juice Bench Press

I am of the opinion that beetroot juice DOES help with performance for higher rep sets and endurance activities.

Beetroot juice has been consistently shown to help endurance activities and improves exercise efficiency. When it comes to resistance training though, that study is really the only relevant one at this stage.

In addition to this, we have no evidence that the consumption of beetroot juice has any carryover to either improved hypertrophy or maximal strength.

It could be worth taking, but I do believe that these studies have been cherry-picked to put it in the best light possible. If it actually had as big of an impact as these studies indicate, across the board, I would be trying to get all my athletes onto it.

Cancer and Animal Products

While I mostly wanted to keep this article focused on athletic performance, they did touch on health quite a bit, including cancer.

One of the strategies to make this point was flashing a whole bunch of studies that appear to link meat and dairy with cancer.

Almost all of the studies shown are observational epidemiology studies.

While these types of studies can show correlations, it is difficult to draw strong conclusions from them since there are so many variables that are uncontrolled.

Types of epidemiological studies

While I think they are worthwhile, it is also worth being aware of the concept of “healthy user bias.”

What I mean by that is that a lot of people who follow vegan or vegetarian diets are also likely to be implementing a lot more health-seeking behaviours in comparison to the average person. Particularly in comparison to those who consume a lot of red meat or processed meats.

This could mean that somebody who is vegan or vegetarian is also more likely to exercise more, limit added sugars, have a higher fibre intake, drink less alcohol, be less likely to smoke and a whole bunch of other variables.

And one massive variable that is super important to be aware of is that on average, vegans consume ~600 fewer calories per day. This alone has a massive impact on reducing the risk of cancer and chronic diseases.

That being said, there are some studies that make an attempt to control these variables a bit more. For example, there is a study that included a sample size of 11,000 participants made up of “health-seeking” vegetarians and non-vegetarians.

After 17 years, there was no difference in the mortality rate. This is an indication that health-seeking behaviours are far more important than the elimination of meat consumption.

When it comes to dairy, as Chris Kresser mentioned on the podcast, the largest meta-analysis on the topic highlighted that 84% of the studies showed no association with cancer or a decreased risk of cancer with dairy consumption.

To break that data down more, 13% showed a decreased risk of cancer, 71% showed no association with cancer and 16% showed an increased risk of cancer.

Dairy and Cancer Meta-Analyses

In my opinion, you need to be quite biased to twist that data into making it look like dairy and cancer are strongly linked.

As an example of how this bias could be displayed, James pointed out that you can then twist that data to say that “87% of studies showed that dairy either increased the risk of cancer or did not decrease the risk.”

That was more of an extreme point to show how Chris had utilised the numbers in a way that suited his argument. Smart debate tactic from James here.

Either way, while both statements are factually correct, I believe it is a fair statement to say that 84% of studies showed no association or a decreased risk. And a fair statement to say that there is a wealth of data highlighting that dairy consumption, in general, is not really associated with cancer risk.

When you dig into the details though, although dairy is not linked with cancer in general, it does appear to have a bit more of a link with increased risk of prostate cancer.

And to be specific, this was actually the claim that was made in the film. I’ve double-checked to confirm and while it seems like they implied that dairy is linked with cancer in general, they only actually mentioned prostate cancer when they were talking about dairy.

When it comes to general health beyond just looking at cancer, moderate consumption dairy is actually linked with a 25% reduced risk of all-cause mortality and higher intakes are still not associated with increased risk of mortality.

Obviously, if you consume a lot of calories through dairy and that increases your total calorie intake to an excessive level, that is going to have negative health implications. That is common sense. But the key point is that a moderate amount of dairy within the context of a good quality diet is certainly not going to be causing harm from a health perspective.

From my perspective, if people did focus more on plant-based diets, their risks of poor health-related outcomes would improve. But I think that would more come down to improving diet overall since the majority of people do not have great diets to begin with.

There is no reason why people cannot include these health-promoting behaviours while also consuming leaner cuts of meat and also consuming moderate amounts of dairy in the context of an overall healthy diet.


One of the great aspects of this documentary was that ethical points were not mentioned until later on in the film.

I classify myself as an expert when it comes to nutrition. That is my passion. I would never say the ethical debates are not important, because they are. But I do not know the ins and outs of them as well as I know nutrition.

Regenerative Agriculture

For example, I am of the understanding that decreasing the consumption of meat is going to be beneficial from an environmental and climate change perspective. But I do not know the ins and outs of how things like regenerative farming strategies stack up in the context of things.

Obviously, you can also bring animal cruelty into the debate and a lot of other relevant points.

If I start talking about areas like that and give inaccurate statements, that then undermines the credibility of the things I say that I have spent the majority of my career learning about, through both formal training and informal study that is always ongoing.

One reason why I say it is one of my favourite aspects is that a lot of plant-based activists link the nutrition aspect and the ethical aspect together. And they twist nutrition facts based on the ethical side of things.

In this case, the documentary did a great job of separating both of those points, while still delivering the overall messages they wanted to say.

They literally waited until roughly an hour in to introduce topics such as animal poaching, land use issues, deforestation, and water usage issues.

The ethical aspects are important and need to be considered. But in my opinion, it is important not to let your perspective on one aspect of a topic cloud your judgement when it comes to another separate aspect. 

Plant-Based vs Omnivorous Diets for Performance

The question on a lot of athlete’s mind after watching this documentary is “will switching to a plant-based diet help improve my performance?”

Firstly, I wanted to highlight that the terminology of “plant-based” is not really defined in the film. They reference anything from vegan to The Mediterranean Diet (which includes a decent amount of animal products) type studies based on whatever suited their points best.

But my understanding based on how it was discussed is that “plant-based” was being discussed as if it were similar to a vegan diet (i.e. no animal products) but without that definition.

Since although it actually is not discussed much outside of vegan circles, veganism is actually defined as “a way of living which seeks to exclude, as far as is possible and practicable, all forms of exploitation of, and cruelty to, animals for food, clothing or any other purpose.”

Therefore, veganism is not a diet. It involves so much more. “Plant-based” typically means just the dietary aspect. For the sake of this discussion, that is how I am referring to “plant-based”.

So, will switching to a plant-based diet improve performance?

Potentially it will.

But my thought process is more along the lines of, if you switch from an optimised omnivorous diet to an optimised plant-based diet, it will not have any noticeable impact on your performance.

It is hard to back that statement up with research since it is like attempting to summarising all of the concepts of nutrition for performance. But there are reviews showing no difference in performance between vegetarians and omnivores.

These reviews highlight that you can compete on an even playing field without a disadvantage as a plant-based athlete, but it also is not superior.

Onto the topic of anecdotal evidence though. There are quite a few cases where people switch to a plant-based diet and their performance improves. There are also cases where the opposite happens. This is more down to the overall change in the diet and certain factors than whether it was plant-based or not.

And using anecdotal evidence has a lot of flaws in general.

Usain Bolt

For example, Usain Bolt claims he was eating over 100 chicken nuggets per day at the Beijing Olympics. In his prime, he was the fastest man alive. Does that mean it is a good idea to eat follow that dietary practice? I would not say so. There is more to it.

To add to how anecdotal evidence can be misrepresentative – if an athlete is carrying more body fat than they should for their sport and they reduce their calorie intake, their body fat will decrease, and their performance will improve.

Switching from a poor diet to an inadvertently lower-calorie plant-based diet is going to lead to improved performance. But so, would have decreasing calorie intake alone.

One of the reasons why The Game Changers is successful is because people are not particularly interested in nuanced concepts, or constantly hearing things like “it depends” and “potentially.” They want it to be black and white, with very little grey area.

This is exactly how The Game Changers makes things looks. It is portrayed as though plant-based = good and animal products = bad. It is also kind of laid out like plant-based = more carbs and omnivorous = fewer carbs.

It is kind of like the below image from Jacob Schepsis in his review of the documentary:

Option A vs Option B

It is laid out like option A vs option B. In reality, there are endless different ways you can structure your diet.

Another key point worth mentioning is that a lot of athletes do not have great diets to start off with. And they also often do not have great nutrition knowledge.

Vegetables are not the be-all and end-all for athletic performance. But they certainly can help. This documentary did a great job of highlighting that.

One of the athletes (Bryant Jennings, I believe) said he barely ate veggies as a kid, ate a lot of KFC and had terrible nutrition knowledge. I am sure his diet improved over time anyway, but I guarantee it got better when he switched to a plant-based diet.

Bryant Jennings The Game Changers

It was not because he switched to a plant-based diet though. It was because he switched to a more optimised diet for performance.

So long as you are meeting the criteria for a good quality diet for performance and your individual needs, it does not matter if the diet is plant-based or not.

For most athletes, I encourage increasing their intake of plant-based foods. Most athletes have a lot of areas in their diet that they can improve upon. The benefits can be obtained on either an omnivorous or a plant-based diet.

My view is that aiming for elite performance is NOT a reason to not switch to a plant-based diet. If it is well-constructed, it will not harm your performance. But if you already had an optimised omnivorous diet, it would not help your performance either.

Nutrients of Importance for Strict Vegan/Plant-Based Diets

Plant Based Nutrition

While a plant-based diet can be equally as effective, there are some nutrients that need to be included more strategically.


As mentioned earlier, it can be difficult at times to consume enough protein, while also not exceeding your calorie budget.

Consuming a diet that has inadequate total protein, or is noticeably lacking particular amino acids is likely going to be detrimental for performance.

Vitamin B12

Vitamin B12 is almost exclusively found in animal products. Due to this, it is almost mandatory that people following exclusively plant-based diets will need to either supplement B12 or choose foods that are fortified with B12 like nutritional yeast.

The symptoms of a B12 deficiency can often go unnoticed until irreversible implications have occurred, so it is a good idea to get a blood test regularly.

This is an important point that everybody should be aware of prior to transitioning to a plant-based diet.


Since dairy is such a convenient source of calcium, it becomes a bit more difficult to consume sufficient calcium on a strict plant-based diet.

Dark leafy greens, almonds and calcium set-tofu can be great additions to the diet to help meet this target, but it is important to do your homework and ensure you are consuming sufficient amounts.

A well-planned plant-based diet can ensure that you are not doing anything that encourages the loss of bone mineral density. If you do not reach your calcium needs through food, it could be worthwhile considering calcium supplementation.


Iron is another nutrient that can be more difficult to meet the needs of while on a plant-based diet.

Heme iron is found in animal iron sources and is more easily absorbable than non-heme iron in plant sources.

Therefore, it is important to focus on not only consuming sufficient iron through foods such as lentils dark leafy green vegetables but also strategies to improve absorption.

For example, consuming vitamin C around the time of having some iron-based foods can help absorption.

Meanwhile tea/coffee can reduce absorption, so you would likely want to consume them away from when you are having iron-rich foods.

Planning your diet well and potentially supplementing when necessary can help prevent downsides related to iron deficiency.


Zinc is also easier to absorb from animal sources. To ensure that you are getting enough zinc, it is important to focus on consuming zinc-rich foods such as seeds, nuts and legumes.

Vitamin D

Vitamin D deficiency appears to be slightly more common in people who follow plant-based diets.

Although there are still some dietary sources available (such as mushrooms that have grown in the sun), to help address this the main strategy is to ensure you get enough sunlight, while also monitoring your levels through a blood test.

If your levels are consistently low, it would be worth considering supplementation as well.

Omega-3 Fatty Acids

Omega-3 fatty acids have a lot of potential benefits such as reducing inflammation (which was a common theme in this documentary) in addition to being beneficial for heart and brain health.

Fish is typically the first thing people think of when it comes to omega-3’s but you can still get them from plant-based foods such as walnuts, chia seeds and flax seeds.

Positive Takeaways From The Game Changers Documentary

Overall, I think the highlight of the documentary for me is that it showed that athletes can follow plant-based diets while excelling as athletes at the elite level.

This has been demonstrated for decades, but it was great that the documentary highlighted it and brought it to the masses in an entertaining way.

I am also a fan of how it focused on the importance of focusing on a nutrient-rich diet. Nutrition involves so much more than just calories and macros, and although you could argue that a lot of studies were cherry-picked, they did highlight a lot of aspects worth thinking about.

It also seems to have made people think about their diets more in general and how they can improve their diet. Due to how it was presented, I am aware of quite a few people who previously did not care about there diet suddenly take an interest.

While I think the documentary is not a great representation of the nutrition evidence we have available, I think it is a great intro for a lot of people that can get them going down the rabbit-hole of learning about nutrition.

Personally, I started my nutrition journey by learning about nutrition from random bro’s on the forums section of Was that the most evidence-based way to learn about nutrition? Hell no.

But that start got me interested and encouraged me to educate myself more.

That perspective allows me to see this in a way that at least I am sure The Game Changers has gotten a lot of people interested in nutrition. It is not an educational resource and it is not the best place to learn about nutrition, but it can be something that encourages people to dig deeper and improve their knowledge about nutrition, health and performance.

By Aidan Muir

Aidan is a Brisbane based dietitian who prides himself on staying up-to-date with evidence-based approaches to dietetic intervention. He has long been fascinated by all things nutrition, particularly the effects of different dietary approaches on body composition and sports performance. Due to this passion, he has built up an extensive knowledge base and experience in multiple areas of nutrition and is able to help clients with a variety of conditions. One of Aidan’s main strengths is his ability to adapt plans based on the client's desires. By having such a thorough understanding of optimal nutrition for different situations he is able to develop detailed meal plans and guidance for clients that can contribute to improving the clients overall quality of life and performance. He offers services both in-person and online.