The Game Changers - A Scientific Review with full Citations

The Game Changers - A Scientific Review with full Citations


I would like to preface this post by saying that I do not have anything against plant based eating. I know plenty of vegans and I respect their reasons for making that decision. I have an explorative mind and am always interested in learning more about nutrition and ways of living that are different than my own. What I have an intolerance for is misinformation, misrepresentation, and fear mongering, especially with regards to food. Choosing to not eat meat or to follow a ketogenic diet because you have educated yourself on that decision is one thing. Being bullied into that decision out of fear of disease, death, or obesity is another and I believe The Game Changers is bordering on the latter. What is important to remember with any documentary is that there are two sides to every story. I have now watched this one twice. The first time I was hopefully optimistic that new information would be presented in a healthy way and easy to digest format. While the format is easy to digest, I found the information to be largely misleading. After scouring the film’s website and credits for a list of citations, I discovered there was none (despite many studies and journal articles being referenced during the film). The second time I watched it, my purpose was to collect, consolidate, and understand the scientific references being made during the documentary. Not surprisingly, I found the vast majority of them to be taken well out of context.

Background on Nutrition Studies

Many of the “studies” in existence and referenced in this film are based on observational studies. Those come in the form of cross-sectional studies, prospective studies, and retrospective studies. Essentially, researchers observe what people eat/ate and relate it to what diseases or health issues they get/have.

Methods of food reporting include single day dietary recall interviews, food frequency questionnaires (most common), and even 7 day dietary recall interviews where they ask specific questions about foods consumed several days prior. The biggest limitation of observational nutrition studies is the inaccuracy of diet reporting. People under estimate, over estimate, forget, and even consciously leave out what they eat.

In a recent article from the Mayo Clinic Proceedings, it is stated that nutrition studies “cannot be reliably, accurately, and independently observed, quantified, and confirmed or refuted,” they do not follow the scientific method and should be regarded as “pseudoscience” at best”

There are a handful of studies included in this film that are pilot studies consisting of a very small collection of test subjects and most of the results have not been duplicated. These studies almost all conclude with something along the lines of “further investigation is needed”. The filmmakers leave this out.


The Game Changers is a sleek new documentary that advocates for the plant based lifestyle by highlighting the heath and performance benefits of veganism over a traditional omnivore diet. It is lead and narrated by James Wilks, a UFC fighter and elite special forces combat trainer.

James navigates through the documentary, interviewing several elite athletes who have made the switch and highlights “groundbreaking” science that substantiates the claims that plants are the ultimate super food and that animal products are… poisonous.

Throughout the documentary, there is a prevailing suggestion that the majority of people are under the impression that performance and energy comes from protein. They lean on this outdated notion hard. When talking about athletes specifically, James replaces the word “carbohydrate” with “plant” which is important when there is an agenda in place.

Who is behind the film

When you get funding for a research study and that study is published in a peer reviewed journal, there are laws in place that require the author and journal to disclose what organizations are involved in the design and funding of the study. This is so any potential conflicts of interests or bias are disclosed.

The thing about documentaries, which are more easily digested by the general public than peer reviewed science, is that there is no such law in place. Producers of documentaries are going to tell you whatever story they want. They might use anecdotal evidence and even flash some studies across the screen to bolster those claims (even if those studies are taken far out of context). But there is nothing that requires them to tell you where the money is coming from.

If you follow the money in The Game Changers, this is what you will find:

James Cameron, Executive Producer – award winning film maker (Titanic, Avatar), story teller, and founder and CEO of Verdiant Foods, an organic pea protein company with the goal of becoming “the largest pea protein fractionation facility in North America.”*

Suzy Amis Cameron, Executive Producer – Founder, Verdiant Foods

Jackie Chan, Passionate Vegan Famous Person

Arnold Schwarzenegger, Ex-Meat Eater, Governator, Passionate Vegan Famous Person

Almost all of the medical professionals interviewed in the documentary also sell vegan products.

Dr. Dean Ornish – Author, “Undo-it!”, leads vegan retreats and sells online programs.

Dr. Aaron Spitz – Author, “The Penis Book”, plant based book on penile function.

Dr. Robert Vogel – Author, “The Pritikin Edge”, plant based book.

Dr. Caldwell Esselstyn – Author, “Prevent and Reverse Heart Disease”, “Cookbook”, plant based lifestyle and cookbook as well as accompanying DVDs.

Dr. James Loomis – Contributor, “Forks over Knives”, plant based meal planning service and publication company.

Dr. Scott Stoll – Author, “Alive” and “Kristin’s Healthy Kitchen Recipes”.

Dr. Kim Williams – Vegan Cardiologist

Dr. Columbus Batiste – Contributor, “Forks over Knives”

Ok, so what’s the deal with James Wilks?

 In 2011, James suffered a serious training injury that put him out of training and work. Unable to teach or train for 6 months, he spent 1,000 hours reading peer reviewed research on nutrition. In case you didn’t math that out, 1,000 hours is 8 hours of reading and research per day for 125 of the 180 days he was out of training. What’s interesting is that he didn’t notice that there is a massive void of scientifically valid nutrition studies available. This is supported by the fact that almost none of them have been successfully repeated.

Growing up, James idolized Bruce Lee, in part because he was able to combine multiple disciplines of martial arts to create his signature (and effective) style of fighting. There is a quote from Bruce Lee at the very beginning of the film that is extremely important. It goes like this:

“Research your own experience.

Absorb what is useful.

Reject what is useless.

Add what is specifically your own.”

This an important philosophy to keep in mind when watching any documentary.

The Gladiators

The documentary gets off to a compelling start when James starts talking about the Roman Gladiators. The original professional fighters. James quotes a study that reports that gladiators didn’t eat meat. Only, it’s not actually a study, it’s an article. And in that article, Andrew Curry highlights that gladiators ate “a vegetarian diet rich in carbohydrates with the occasional calcium supplement.”

There is no mention that the gladiators ate no meat, they just ate a high proportion of carbohydrates (plants) to help with performance and because they needed to be a little… fat. Fat gladiators were harder to kill.

To further bolster their argument, a researcher removes and grinds up a cross-section of gladiator bones and explains the phenomenon of “Strontium” which is a mineral that is found in high concentration in plants. He then demonstrates a test where a sample is introduced to flame and if the strontium level is low (meat eater) the flame will remain blue. If the strontium level is high (plant eater), the flame will turn red. The flame turns red! Wow. Gladiators were vegetarians after all!

Except that they weren’t. What is important to note here is that there is a big difference between “Carnivore” (one who only eats meat) and “Omnivore” (one who eats both meat and plants) and that difference is also reflected in the relative strontium levels in the bones. The Carnivore with low strontium (low enough to not create a red flame) would be an apex predator, eating only meat. Omnivores on the other hand would consume a moderate amount of strontium (from plants) in comparison.

Here are the relative ranges of strontium present in each type of diet:

  • Herbivore (400-500ppm)
  • Omnivore (150-400ppm)
  • Carnivore (100-300ppm)

As you can see, there is a fair amount of overlap between the three types of diets. The fact that Roman Gladiators ate a lot of plants is accurate. The argument that the ate “all” plants is not.

For the record, the strontium flame test has its own set of issues. For example, if it is used to analyze populations that ate mollusks or other shellfish, which, like plants, are known to have high levels of strontium, the flame test will burn red despite it being a meat eating population. *

Plant Based Athletes

Arguably the most compelling part of the documentary is the inclusion of elite athletes who have made the switch to a plant based diet.

They start off by highlighting the Connor McGregor vs Nate Diaz fight from 2016 in which Connor (meat eater) is defeated by Nate (plant eater). Frankly, it seems as though (because they provide no actual data on macronutrient ratio) Connor eats too much meat and probably not enough carbs. He brags about this, saying he routinely eats steak for breakfast, steak for lunch, and steak for dinner. Nate eats a plant based diet, which is also known as a diet that is VERY high in carbohydrates.

They highlight that Nate was only given 11 days’ notice of the fight, after UFC Lightweight Champion Rafael dos Anjos broke his foot. This paints Nate as the underdog. What they failed to mention was that Connor had to go up 2 weight classes to fight Nate, and was between 15-20lbs lighter than Nate in the ring. Convenient oversight. Connor probably did need to eat more carbs, but he also got beat by someone who was just… bigger.

They throw in some other athlete highlights here.

Scott Jurek, Ultra marathon runner.

Morgan Mitchell, 400m sprinter.

Dotsie Bausch, Cyclist.

Ultra running, sprinting, and cycling all require massive amounts of carbs. There is no mention from any of these athletes about what they were doing before. They could be (and probably are) simply eating more carbs.

James wants to see the impact of plant based eating on strength athletes, so he goes in search of “the big boys”. I’ll ignore the gross male superiority theme that rules the film from here on out.

Kendrick Ferris, Olympic Weightlifter.

Patrick Baboumian, Strongman.

Bryant Jennings, Boxer.

Derrick Morgan, Linebacker.

Again, not much mention of what diet and training looked like before except that Bryant and Derrick both admit to having a fondness for fried chicken. What a revolution, when you replace low quality fast food with a diet full of whole foods you start to feel and perform better.

Interestingly, Ilya Ilyin (Kazakhstan) is also a vegan and a much more successful weightlifter than Kendrick (2x Olympic champion in the same weight class) but he was later stripped of his titles after his samples were retested positive for anabolic steroids. Probably not the narrative they want here.

Patrick Baboumian claims to have gained 25kg after switching to a plant based diet. Again, no mention of calorie intake before/after switching to a Vegan diet. If calorie intake is higher, weight gain will occur. And while Baboumain’s yoke carry at the end of the film is impressive, he has never been very competitive on a world stage. He specializes in niche strongman events like yoke carry and front hold.

There is a quote in this part of the documentary that is accurate however. It’s from Dr. James Loomis and he says: “The actual energy for exercise comes mainly from carbohydrates.” When we sacrifice carb calories for protein calories it leads to chronic fatigue, loss of strength, loss of stamina…” Again, this does not suggest that only plants should be consumed. It suggests that carbs must be consumed in order to perform at a high level.

While the testimony from the athletes is compelling and riveting, it is without scientific control or evidence and therefore anecdotal with respect to the argument being put forth.

Protein Quality Plants versus Animals

The filmmakers argue here that plant based foods are high quality and actually better and more complete sources or protein than animal based foods. Here is what the science actually says:

“Complete Protein” – contains all the essential amino acids in adequate amounts. Incomplete proteins are either insufficient in amounts of one or more EAA or devoid of them all together. Animal proteins have all the EAA you need to function in the correct amounts. Plants on the other hand, do not. While some may contain all of the EAA, you will have to combine plants to ensure you’re getting all EAA and in the right concentrations.

“Quality” with regards to protein pertains to its bioavailability, and your body’s ability to digest it. To over-simply this concept a bit, an egg is considered a perfect protein, scoring 100%. Beef is a close second at 92%. The highest vegetarian source we have is a kidney bean which scores at 54%. *

The documentary cites the largest cross-sectional study ever done to compare diet patterns across populations of people.

The argument is that plant eaters not only get enough protein, but 70% more than they need and that meat eaters still get roughly half of their protein from plants.

Those numbers (from the cross-sectional, survey based study of 71,751 subjects) look like this:

Strict Vegetarian:

Total protein per day (median): 70.7g

  • Total protein from plants (median): 67.7g
  • Total protein from meat (median): 2.5g (weird)
  • Total protein from dairy (median): 0.6g (weird)
  • Total protein from soy (median): 10.9g


Total protein per day (median): 74.7g

  • Total protein from plants (median): 42.7g
  • Total protein from meat (median): 29.4g
  • Total protein from dairy (median): 9.3g
  • Total protein from soy (median): 2.8g

Some important things to highlight:

The recommended daily protein intake (according to James) appears to be about 50g per day.

Meat eaters are still eating more protein than vegetarians.

There’s a funny bit here where they reference a peanut butter sandwich as containing an equivalent amount of protein to 3 ounces of beef. To achieve the ~20g of protein that is in 3 ounces of beef, you would need to consume 5 tablespoons of peanut butter. Which also contains 40g of fat and comes in at 470 calories.

**Edit, it has been pointed out that the bread in the sandwich would also contain protein, which is true. Assuming 2.5g protein per slice of bread (sandwich bread), that would reduce the required amount of peanut butter from 5 tablespoons to 4 tablespoons brining the total to 510 calories, 20g protein, 34g fat, and 39g carbs.

Endothelial Function Test

 This is one of my favorite parts of the documentary because the “science” is so convincing on a surface level. Three Miami Dolphins players arrive at a doctor’s office to take part in a test, or rather a demonstration, to assess endothelial function after eating either a plant based burrito, a chicken burrito and a red meat burrito. Endothelial function has to do with the relative viscosity of the blood which is affected by diet, hydration, blood volume, oxygen concentration, and a number of other factors. But in this study, we are attributing it to a burrito…

One of the players was vegan and the other two like fast food. Even before the burritos were consumed, there is a stark difference in diet quality. They first compare blood cells from the fast food fellas to the vegan and to everyone’s surprise, the vegan showed superior endothelial function. Then the next day, they feed all three athletes bean burritos and compare blood to the previous day’s meat burritos and again, much to no one’s surprise, the blood following a bean burrito shows superior endothelial function. Or at least it looks cleaner. Ah the ‘ole calibrated eyeball analysis…  Did I mention this test is not scientifically validated? Other contributing factors such as sleep, training, hydration, stress and what else they ate that day were also ignored.

There are some studies that are flashed across the screen here, notably one that suggests the ingestion of hass avocado could modulate the inflammatory response caused by one hamburger meal. Of note, this pilot study of 11 people was funded by… Hass Avocado Brand.

James suggests that he has found a large body of research showing that plants have the opposite effect as meat on endothelial function. The filmmakers flash approximately 20 journal article references across the screen while touting the benefits of plants on endothelial function in contrast to the harm of animal protein with absolutely no mention of the proposed mechanism of action. I am including all of those studies in this review, but the main takeaway is that the ingestion of grape juice, blueberries, chokeberries, black tea, green tea, spinach, apples, dark chocolate, boysenberry, raspberries, and similar foods can improve endothelial function, increase phenolic metabolites, improve vessel function, lower blood pressure, and improve platelet function. In none of these studies is it suggested that meat should be removed from the diet. These studies simply suggest what we already know, and that is the inclusion of a variety of fruits and vegetables can improve many health markers.

The Beet Root Bench Press

Shortly after the endothelial portion of the documentary, James points out that beet root juice can improve your bench press (the manliest of lifts) by 19%. So if you’re a 225lbs bench-presser you can expect a 270lbs bench after a big ole glass of… wait no that’s actually wrong.

What he cites here is not actually a study, it’s a research article looking for evidence to substantiate this claim. Here’s where they end up: “Results indicate that beetroot juice given as a single dose or over a few days may improve performance at intermittent, high-intensity efforts with short rest periods. The improvements observed were attributed to faster phosphocreatine resynthesis which could delay its depletion during repetitive exercise efforts. In addition, beetroot juice supplementation could improve muscle power output via a mechanism involving a faster muscle shortening velocity. The findings of some studies also suggested improved indicators of muscular fatigue, though the mechanism involved in this effect remains unclear.” They also recognize that the amount of data available is extremely scarce.

Antioxidants and Inflammation

In this part of the documentary, they point out that a head of iceberg lettuce contains more antioxidants than a piece of salmon. They may as well have said that a carrot has more fiber than a meatball. Antioxidants are far more abundant in plants than animals simply because the majority of them are vitamins and minerals. Micronutrients are degraded in the digestive tract of an animal. Yes, one of the benefits to eating plants is that you get LOADS of antioxidants. Eating meat does not negate the positive impact of those antioxidants.

There was statistic in this part of the documentary that “switching to a plant based diet can reduce inflammation by 29% in just 3 weeks.”

While this study does show that adding fruits and vegetables to your diet decreases C-Reactive protein, it does not recommend a plant exclusive diet. The researchers also recognize that it is limited in scope at 3 weeks and there was no follow-up assessment done.

Animal Protein and Heart Health

The heart health debate is always a popular topic in the vegan world because of the cholesterol lowering abilities of a plant based diet. This is also the part of the documentary where James highlights his father’s health struggles. He’s recently had a heart attack because he likes to eat meat (pies). Specifically, pork pies… They also bring fire fighters into the debate, a demographic of people who demonstrate a consistent lack of concern for dietary health of any kind.

Most of the studies cited in this portion of the documentary do acknowledge the positive effect that plant intake has on heart health, specifically lowering risk factors for heart disease. They did not specifically recommend a cessation of animal product intake and acknowledged the contribution of other factors such as smoking, stress management, and exercise. It was further noted in one of the studies that large randomized intervention trials on the effects of vegetarian diet patterns are warranted in order to make meaningful recommendations.

Cancer Risk

This is a fun part of the documentary where they equate the consumption of meat to cigarette smoking. While there might be some correlation between meat consumption and cancer (or at least the conditions under which meat is consumed), there is certainly not the same causation that is now associated with cigarettes.

The filmmakers cite a study here that was done over 6 years in a low-risk population of non-Hispanic white members of a health study who had no documented history of cancer. The subjects that exhibited the highest risk of colon cancer were those with high red meat intake, low legume (bean) intake, and high body mass index (they were fat). The increased risk due to red meat intake reflects a more complex etiology than simply “red meat causes colon cancer.” Which means there are likely many other cofactors that contribute to the correlation, such as what is being consumed frequently with red meat (french fries, bacon, ice cream, etc.) and what type of activity occurs during the day.

I would be remise not to mention that there is growing concern in the scientific community regarding the preferential exposure to pesticides for which fruits, vegetables, and cereals are the main contributors. The vegetarian population may be more exposed to pesticide residues than the general population due to specific dietary habits. Thus, this population should be considered for risk assessment of pesticide residues. Known risks of pesticide residues includes the development of cancer.

Ancestors were Vegetarian

In this part of the documentary, the filmmakers try to convince us that because our teeth are flat, we have full color vision, long intestinal tracts (relative to a carnivore), and we don’t make our own vitamin C that we, as human beings, are not meant to eat meat.

Yes, early human beings did eat plants. But does that mean we should only eat plants? Did they ever eat meat? Yes, in fact they did. We know this because we have evidence of it. Before agriculture and the domestication of farm animals, humans were hunting and gathering. And they weren’t hunting fruit.* In fact, some cultures survived predominantly on meat and animal fat alone (Inuit). Does this mean we should eat only meat? No! We should eat a balance of both. Because humans are omnivores.

To finish this segment, the filmmakers mention that glucose is our primary fuel source and we are clearly meant to only eat plants since they are the best source of fuel. Ok, so glucose might be our preferred fuel source, but we are also equipped with a nifty little metabolic back up mechanism called “gluconeogenesis” which allows us to produce sugars (glucose) from non-carbohydrate precursors (like protein and fat).

What about Testosterone?

In this portion of the film, they bring the super scientific burrito method back except this time we are measuring erectile strength and frequency at night time. Again, three male athletes get a meat burrito one day and a bean burrito the next. Big surprise, the test results came back in favor of the bean burrito. Given the stunning difference in data, it’s surprising these guys were able to sleep on their stomachs! A few important things to remember about this one: This is not a scientifically validated testing method. They provided ONE single data point for each test condition (statistically significant? No chance). And just like the endothelial function burrito test from earlier, this “experiment” fails to consider or attempt to control variables like sleep, muscle fatigue, training volume, stress, hydration status, salt status, alcohol consumption, medical history, or genetic predispositions.

 Using these observations to firm up his argument, James goes on to note that “Studies comparing men eating animal protein and men eating plant protein have demonstrated no difference in testosterone levels.” This is wrong. Simply reading the journal articles cited in the documentary confirms that. The filmmakers claim that vegans actually have higher testosterone than meat-eaters. They also tactfully omit a really important difference between vegans and meat eaters. While some studies found total testosterone to be higher in vegans, multiple studies indicate that sex hormone-binding globulin was also substantially higher in vegans. Because SHBG binds to sex hormones (testosterone) the actual amount of free testosterone was equal between the vegan and meat eating group. This is a convenient detail to leave out.

On estrogen, the filmmakers lean into the dairy industry, saying that “simply drinking cows milk can increase a man’s estrogen levels by 26% while dropping testosterone levels by 18%”.

This particular factoid is from a pilot study performed on 7 men drinking milk exclusively from pregnant cows. The purpose of this study was to evaluate the impact of drinking milk specifically from pregnant cows and not to serve as a model for dairy consumption as a whole.


“Research has shown that people who replace animal foods with high carbohydrate plant foods experience an average drop in cortisol levels of 27%”

This might be my favorite example of cherry picking and re-wording in the whole documentary. What the actual study has to say is that the ratio of protein and carbohydrate in the human diet has a major impact on cortisol and testosterone levels. It does not say that animal protein should be replaced with plants, but rather more carbohydrates should be consumed in relation to protein of any kind in order to decrease cortisol and increase testosterone.

Muscle Building

This is the body building part of the documentary where we get to examine genetically gifted individuals and their propensity for building lean body mass regardless of type of intake. We know that free testosterone remains the same between vegans and meat eaters, so we can assume that muscle building ability should be the same between the two groups if intake of essential amino acids, macronutrients, and calories are controlled and comparable. But who am I kidding, they don’t care to actually do science here.

“Unprocessed carbs are associated with decreased body fat.” … unless you’re eating too many calories.

The filmmakers continue to flash studies across the screen to support the superior muscle building properties of plants, so I want to highlight some of the conclusions from those studies:

“There is insufficient evidence to make clear conclusions about the protective effect of legumes on weight.” *

“The present meta-analysis seems to be limited by low study quality.”*

“Our results suggest that a ketogenic diet might be an alternative dietary approach to decrease fat mass and visceral adipose tissue without decreasing lean body mass; however, it might not be useful to increase muscle mass during positive energy balance in men undergoing RT for 8 weeks.” *

The study above is actually a weight loss study that the filmmakers try to use to support the massing effects of plants. When really, the carb (plant) eating control group just had trouble losing weight as effectively as the keto group.

Meat and Dairy / Mortality

Here they bring back the cigarette references which frankly is making this documentary feel a lot like “Fed Up” which is probably not the vibe these guys are going for. But here we are.

According to James, there is “overwhelming scientific evidence connecting animal foods to many of the most common deadly diseases”

The first study he cites is one about falling down. Yes, the deadly disease of falling down. The authors of this journal article acknowledge that because of the possibility of residual confounding and reverse causation phenomena, a cautious interpretation of the results is recommended. This is science jargon for “take this data with a grain of salt.”

In another study taken out of context, the researchers actually come to the conclusion that egg consumption is not associated with the risk of cardiovascular disease and cardiac mortality in the general population. *

The real kicker in this part of the documentary is that James/the filmmakers get very upset because the meat and dairy industry have funded a handful of studies that appear to debunk the message the filmmakers are trying to get across. Organizations like The Dairy Council, The Cattlemen’s Beef Board, The Egg Nutrition Center, and National Pork Board are flashed in angry letters across the screen in a “how dare you have an agenda” kind of tone.

The irony of this is almost too much to take because if you look into funding for some of the aforementioned studies, you will find Hass Avocado and The North America Tea Trade Health Research Association. Not to mention the pea protein company that is funding this entire documentary and the lineup of medical professionals who all have a vegan agenda! Like seriously, you want to get salty here James?

Only Valid Point Made – Farming

The last part of the film is compelling and it highlights a major issue with our industrial society today. As it stands, livestock production uses 83% of the world’s farmlands and an unreal amount of water. To be honest, there is a lot of waste in farming and sustainability should be considered. If you want a real case for “eat less meat” it’s here, in this part of the film. The choices we make every day on where to buy our meat will have an impact on the future of farming. Buying meat from a sustainable farm that uses pasture management, maintenance of biodiversity, soil management, and water reclamation is a small step in the right direction for building a future for livestock farming.


However well intentioned, The Game Changers misses the mark by being a little too heavy handed with the disdain for meat and the plant based agenda. What I do agree with is that everyone would benefit from including a larger variety of vegetables and fruits in their diets. The science supporting this is sound. What I do not agree with is the idea that it has to be either/or. The fact is, there are plenty of very unhealthy vegans out there just like there are plenty of very healthy meat eaters. The real value is in finding a sustainable in-between that gets you the best of both worlds in a diet that you can live with forever.

And remember what Bruce Lee said:

“Research your own experience.

Absorb what is useful.

Reject what is useless.

Add what is specifically your own.”

The Game Changers References:

The Gladiator Diet

Nutrient Profiles of Vegetarian and Non-Vegetarian Dietary Patterns

These are the studies cited with regards to vegetarian diets for athletes:

Endothelial Function

Beet Root


Plant Based Guide for Physicians

Heme Iron (

Heart Disease

Cancer Risk

 Human Evolution






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