Update (10/12/19) On October 16, 2019, The Game Changers will be available to stream on Netflix. The Game Changers is also available on-demand via the iTunes store.

When the cab drivers at Sundance are talking about a film you made, you know the five years you put into a project were worth every second. This was the “incredible and surreal” experience for producer James Wilks at Sundance in January 2018, when his new documentary The Game Changers made its debut.

Wilks is not only a producer of the film, he’s also the star. A mixed martial artist, winner of The Ultimate Fighter, and combatives trainer for government agencies, Wilks developed an interest in plant-based eating after he experienced a physical setback. In the documentary, he sets forth on a globe-trotting mission to debunk what he calls “the world’s most dangerous myth: that animal foods are necessary for protein, strength, and optimal health.”

The Game Changers—executive produced by three-time Oscar-winner James Cameron (Titanic, Avatar) and directed by Oscar-winner Louie Psihoyos (The Cove)—is now screening at festivals in the U.S. and worldwide, and is slated for public release this fall. In the meantime, we caught up with Wilks to get the inside story.

FOK: What sparked your own journey into the plant-based way of eating?

James Wilks: Shortly after winning The Ultimate Fighter, I was sparring with a future heavyweight champion and tore ligaments in both of my knees. Unable to train for six months, I started researching peer-reviewed science on nutrition, looking for any advantage I could find to get back on track as quickly as possible. That’s when I stumbled across a study about the Roman Gladiators, which concluded, based on strontium and stable isotope analysis, that they ate a plant-based diet.

As a die-hard meat-eater who believed you needed animal protein to be strong, this discovery challenged everything I thought I knew about nutrition, launching me on a five-year quest for the truth in nutrition, modeled after Bruce Lee’s Truth in Combat philosophy: “Research your own experience. Absorb what is useful. Reject what is useless. Add what is specifically your own.”

FOK: What was your transition to plant-based eating like?

JW: The transition was a little awkward at first, since I didn’t really know much about plant-based food. In fact I’d never even been in a vegetarian restaurant. But once I got the hang of it and latched onto some comfort foods—like oatmeal, peanut butter, pasta, and bean burritos—everything fell into place and I started seeing dramatic improvements in my energy, strength, endurance, and recovery.

FOK: When did your quest become a film, and how did your award-winning crew get assembled?

JW: I realized early on that I should start documenting my experiences, so I bought a video camera and some lighting equipment off of Craigslist and recorded my initial interviews with athletes and nutrition experts. Around that time I met Joseph Pace, a seasoned nutrition researcher from Canada with a keen interest in performance nutrition. He convinced me to make a feature-length documentary about my journey, and with some timely guidance from [creator and executive producer of the Forks Over Knives film] Brian Wendel, we started filming in the fall of 2013.

In early 2014 we built a short trailer with hopes of attracting an established director capable of creating a truly cinematic film. We shared the trailer with Louie Psihoyos, the Oscar-winning director of The Cove, with hopes he might be able to recommend someone. His response was: “How about me?”

Shortly after bringing Louie on board, we got a phone call inviting us to meet with James Cameron, who had been following the film’s development. We all flew to Malibu and nearly fell out of our chairs when Mr. Cameron offered to not only join the film as an executive producer, but to also kickstart our fundraising with a large donation.

The rest of our crew—including our writer, Mark Monroe (Icarus, Before the Flood, The Cove), and our editor, Dan Swietlik (Fed Up, An Inconvenient Truth, Sicko)— joined the project shortly after.

FOK: Can you tell us about your journey and some of the people you met along the way?

JAMES WILKS: In the five years since production of the film got underway, I’ve had the opportunity to meet more than 50 athletes from around the globe. These include Olympians, world champions, and world record holders—each of whom have incredible stories and insights to share. Four of the athletes we spent the most time with in the film are strongman Patrik Baboumian, ultramarathoner Scott Jurek, cyclist Dotsie Bausch, and former NFL cornerback Lou Smith, each of whom embody one or more elements of world-class performance, ranging from strength and power to endurance, recovery, and longevity.

We also interviewed more than 30 experts in the fields of nutrition, public health, and anthropology, who also had their own powerful stories and knowledge to share. Among the most interesting to me were Dr. Fabian Kanz, a forensic anthropologist from Vienna who analyzed the gladiator bones; Dr. James Loomis, former team physician for the St. Louis Rams/Cardinals; and Dr. Kim Williams, then president of the American College of Cardiology. Each of them brought an entirely unique perspective to the science supporting plant-based nutrition.

FOK: What are a few surprising things you learned that are revealed in the film?

JW: The film features two live scientific experiments that use elite athletes as test subjects. The first experiment, conducted on three NFL players, looks at the effect a single meal (animal-based vs. plant-based) can have on overall blood flow. The second experiment, conducted on three varsity athletes, looks at the effect these same two meals can have on blood flow to a specific part of the male anatomy, i.e. erectile function. You’ll have to watch the film to see what happened.

FOK: The film recently premiered at Sundance. What was that like?

JW: Every screening sold out and we received multiple standing ovations, which was both incredible and surreal. I think when you spend five years on a project like this you have no idea what it’s going to be like for a first-time viewer. And to be honest, Joseph and I weren’t sure how the audience would respond. To be approached by people on the street saying they’ve been plant-based ever since the screening, or to hear from cab drivers that their previous customers couldn’t stop talking about the film, those were the most rewarding experiences we could imagine.

FOK: What’s your typical training schedule like these days, and what do you eat in a typical day right now?

JW: My training schedule is pretty light these days, at least compared to when I was competing in the UFC. That said, I still lift weights or run every day, and I also do combat training on a regular basis. To be honest it’s my kids who eat up most of my physical energy.

I start most days with a big bowl of oatmeal, hemp seeds, pumpkin seeds, flax seeds, berries, and banana. For lunch I might eat something like a lentil stew with collards and sweet potatoes. Midway through the afternoon I have a shake with plant milk, banana, dates, berries, kale, and a plant-based protein powder depending on my training goals. For dinner I’ll have a tofu stir fry with loads of veggies including red pepper, broccoli, cabbage, carrots, onions, garlic, etc. And then for a late-night snack I’ll have something like a whole grain cereal with apples, figs, and walnuts.

While I eat whole foods the majority of the time, our family also hits up Veggie Grill or Chipotle when we feel like a treat.

FOK: What is the single most important “truth” you hope people get out of watching the film?

JW: That an animal-based diet isn’t natural or necessary, and that a whole-food, plant-based diet is the single most powerful tool we have to improve how we look, feel, and perform.

For screening information and updates, visit gamechangersmovie.com. You can also follow The Game Changers on Facebook and Instagram.