Hollywood director James Cameron has spoken out about the benefits that veganism boasts for the male libido ahead of the release of his upcoming documentary, The Game Changers.

The film illustrates the environmental and health advantages of a plant-based diet, one of which happens to be bedroom-based, Cameron claims.

In an interview with the Toronto Star, the Titanic and Avatar director said he’d “love to put Viagra out of business, just by spreading the word on plant-based eating."

Cameron has followed a vegan diet himself for roughly seven years and hopes that the new feature-length film, which features vegan Olympic athletes and bodybuilders, will help show how beneficial a vegan diet can be from both a personal and global perspective.

He is the executive producer on the film, which was directed by Louie Psihoyos, whose 2009 documentary, The Cove, documents the brutality of dolphin hunting in Japan.

The scene that Cameron believes fully illustrates the benefits of veganism to male sexual health features three men, each of whom undergo on-screen tests conducted by urologist Dr Aaron Spitz, author of The Penis Book.

After each participant is given a special device to monitor penile length and girth, they are revealed to experience “better erections” after consuming a vegan meal compared to when they consumed a non plant-based meal.

While Cameron thinks it could be “the scene of the film”, he explained that one of his main intentions with The Game Changers is to promote veganism to men by debunking the common misconception that a vegan diet is always insufficient in protein.

The film does this by highlighting the myriad plant-based proteins available and interviewing a whole host of famously "bulky" vegans, such as Arnold Schwarzenegger.

As for veganism itself, “I believe in it completely,” the Ontario-born director said.

“More than that, I think that if we don’t make a major shift as a civilisation, and I mean that globally, towards plant-based eating, we’re just not going to make it.”