An Objective and Scientific Game Changers Review

Serdar Tuncali
Nov 3 · 8 min read

Game changers documentary misses an excellent opportunity to educate the public on the importance of plant proteins and the potential benefits of a plant-based diet.

Photo by Victor Freitas from Pexels

With great names such as James Cameron, Arnold Schwarzenegger, and Jackie Chan as producers, Game Changers has impressive resources. As you watch the documentary, it is evident that they put a lot of effort into it. It is cinematically one of the best nutrition documentaries I have seen. I wish they had used these resources to make an objective and educating documentary.

A few years ago, I went to a car dealership to buy a car. I had done my research, and I already liked the vehicle. We just had to agree on the price. The car salesman was pushing so hard to sell me the car, he was making ridiculous statements about the vehicle. The dishonesty of the salesman put me off, and I decided not to buy the car.

I felt the same way as I watch this documentary. I already knew that I needed to eat more plants and get at least half of my protein from plant-based proteins. However, I felt like being manipulated, and some claims in the documentary were insulting my intelligence.

Is Plant-Based Diet Healthy?

I am going to go over the claims in the Game Changers one by one, and give both scientific facts and offer my own opinion. But before I do that, I want to explain where I stand with the whole vegan diet. This way, you know that I am being objective, and I am neither defending or attacking the documentary based on my preconceived ideas.

I believe that a vegan diet can be healthy and sustainable as long as it is carefully designed. I don’t think eating animal proteins is essential. You can get enough protein to be healthy and build muscle with a vegan diet. Therefore, if someone wants to go vegan because of ethical or religious reasons, they have my full support. However, I don’t think a vegan diet is an optimal diet for health and performance.

Now let’s get to the documentary review and the claims featured in the movie.

Game Changers features an MMA fighter James Wilks and his discovery of the plant-based diet following an injury.

At the beginning of the movie, we watch Wilks winning a UFC tournament back in 2009, as a meat-eater. Later in the documentary, we see Nate Diaz, a vegetarian fighter, beating Conor McGregor, a meat-eater, to prove eating meat makes you weak. However, it doesn’t mention that McGregor ended up beating Diaz later that year.

Claim #1: Gladiators Were Predominantly Vegetarian

Possibly Correct — Irrelevant

Photo by Dmitry Mayatskyy from FreeImages

At the beginning of the movie, James Wilks mentions that he read a study about the gladiators’ diet and he found it fascinating that gladiators were mainly vegetarian. However, the piece featured was not a study, but a short article written for an archeology magazine.

The actual study on the subject (1) doesn’t conclude that all gladiators were vegetarians. According to this study, in one location (Ephesus, Turkey) of the Roman Empire, the gladiators were eating mainly wheat, barley, and legumes.

Even if it is true that all gladiators were 100% vegetarian, it actually doesn’t mean anything. First of all, we are talking about the diet of slaves almost 2,000 years ago. It is safe to assume that meat wasn’t an easily accessible food group for everyone.

Furthermore, we are not talking about a developed civilization that has advanced in nutrition science and technology. They also believed that drinking the blood of a slain gladiator cured epilepsy. (2)

Claim #2: Meat is Not a Good Source of Energy?


Photo by Pixabay

James Wilks makes a point about the misconception that meat gives you energy. He watches a vegan ultramarathoner and says, “How can his meat-free diet possibly give him enough energy?”

Dr. James Loomis, a team internist for the St. Louis Rams and the St. Louis Cardinals, points out that athletes have the perception that protein is what sustains energy.

Later on, he explains, if you sacrifice carbohydrate calories for protein calories, muscle glycogen stores will be depleted, which results in fatigue and decreased stamina.

This is all correct. Neither meat nor any other protein, whether animal or plant-based, is not a source of energy.

Honestly, I didn’t even know athletes believed that because it is a well-known fact that protein is not primarily used for energy. It is used for building and repairing.

Claim #3: All Protein Originates in Plants. Animals are Just The Middlemen


The idea behind this claim is that the animals we eat for our protein needs are mostly herbivores. Since they eat plants for their protein needs, why wouldn’t we go directly to the source?

To support this claim, later in the documentary, we hear the vegan strongman Patrik Baboumian say, “have you ever seen an ox eating meat?”

The logic is utterly flawed. First of all, herbivores such as cows have a different gastrointestinal tract than us humans. They can break down cellulose and extract more nutrients out of the plants. We can’t break down cellulose.

Furthermore, even though cows only eat plants, their primary sources of protein are not plants. Bacteria in the gastrointestinal tract of cows degrades the plant proteins and use the ammonia to synthesize microbial protein. Cows then digest the bacterial protein and use it for muscle building and repair.

The majority of the cow’s protein comes from bacteria, not plants. (4)

Claim #4: Plant-Eaters Get More Protein Than the Meat Eaters


This claim is quickly mentioned in the documentary, and a scientific reference flashed on the screen for a quick second to back up this claim.

I was amazed and intrigued, so I paused the movie, looked at the scientific reference (5) to see how it was at all possible. Well, it wasn’t.

According to the study referenced in the documentary, non-vegetarians eat about the same, even slightly more protein than strict vegetarians. So how could they make a false claim like this, while referencing a study that shows otherwise?

What the study showed was vegetarians eat more plant protein than non-vegetarians.

To support the claim that plants are at least as rich sources of proteins as animals, they state that you can get the same amount of protein from a peanut butter sandwich as a 3 oz. steak or 3 large eggs.

3 oz. steak and 3 large eggs contain around 18 grams of protein. They are both somewhere around 200 and 250 Calories. To get this much protein from a peanut butter sandwich, you have to eat over 400 Calories. Not a good idea if your goal is to lose or maintain your weight.

Claim #5: Every Single Plant Contains All The Essential Amino Acids

Technically Correct — Not Practical

A big reason for choosing animal protein over plants is that animal proteins are complete proteins (including all essential amino acids). In contrast, plant proteins are incomplete proteins (lacking one or more essential amino acids).

However, both vegans and vegetarians can get all the essential amino acids from their diets, provided they get their protein from a variety of sources.

Proteins are made of amino acids and digested down into amino acids before providing any benefit inside the body. There are 20 different amino acids, and nine of them are essential amino acids. That means our body can’t produce them, so we need to get them from our diet.

All animal proteins are rich in all the amino acids. Even though plants contain all the essential amino acids, some of them are so low that it is practically impossible to get enough from one plant source.

However, you can get all essential amino acids by eating a variety of plants.

Claim #6: As Long As Proper Amino Acids are Consumed, Source is Irrelevant


I was actually surprised to see this claim in this documentary. After claiming plant-based proteins are superior, they turn around and accept that they are actually not.

Even though you can get enough protein from plants, studies show that specific proteins, namely whey protein, are better for muscle building. (6, 7)

Claim #7: Animal Proteins Cause Heart Disease and Cancer

Insufficient Evidence

There are indeed several studies showing a correlation between high meat consumption and all-cause mortality. However, none of these studies are controlled clinical trials. In fact, such a study could never get IRB approval for ethical reasons.

These studies are observational studies looking at the correlation. It would be safe to assume that people who avoid overeating meat are also more health-conscious. They usually eat healthier and exercise more often.

The Annals of Internal Medicine published a review on red meat consumption. They concluded that there is not enough evidence to recommend reduced red meat intake (8).

Claim #8: Humans Are Not Carnivores


The documentary goes into a detailed explanation to show humans are not carnivores. We look at the archeological evidence and comparison of human teeth and carnivore teeth.

I found this part of the documentary unnecessary because we already know that humans are not carnivores. We are omnivores. Maybe they were just debunking the ideas of people supporting carnivore diets.

Claim #9: Soy Doesn’t Negatively Affect Testosterone Levels


One of the biggest misconceptions about soy products is that they can increase estrogen and decrease testosterone levels in men. However, studies show that reasonable consumption of soy products have no adverse effects on testosterone levels. (9, 10)

My Other Criticism for the Game Changers

Despite some of the incorrect claims about animal proteins and plant-based proteins, my most significant criticism of the documentary is the lack of objectivity.

All the experts interviewed for the documentary are supporters of plant-based diets. There is not a single doctor or scientist interviewed who is not a plant-based practitioner. This lack of objectivity makes it look like all the doctors are recommending plant-based diets.

Another example of a lack of objectivity is that the documentary features athletes who follow a plant-based diet. An objective statement would be “you can still perform at a high level as a vegan”. Instead, the claim is “going vegan is the only way to perform at a high level”. For every vegan athlete, I can show you at least 5 better athletes who consume animal products.

Some of the athletes who claimed that they have improved after switching to the plant-based diet also confessed that they used to eat fast food and fried chicken all the time. It is not a mystery that switching from a diet of fried foods to a whole foods diet will improve performance.


If Game Changers convinced you to give up meat to improve your health and performance, I would recommend fixing your diet first without giving up the animal protein. Eat plenty of fruits and vegetables, healthy fats, and whole grains (unless you have a condition that limits grain consumption), and lean protein from a wide variety of sources.

After following a healthy diet consistently for a while, if you want to swap out animal proteins for plant proteins slowly, go ahead and try and see the effects for yourself.

If you are already a vegan or vegetarian for ethical or religious reasons, you don’t need validation from a documentary or a blogger. Rest assured that you can still be healthy without animal protein.

Originally published at on November 3, 2019.

Serdar Tuncali

Written by

Scientific approach to fat loss and body transformation. Self-experimenting and researching various methods and reporting on

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