Longevity investor Bryan Johnson hosted Kim Kardashian and Andrew Huberman at a ‘Don’t Die Dinner,’ where they discussed their own mortality

How did Johnson assemble such an eclectic group of high-profile people? “They organically form among friends of friends,” Johnson tells Fortune. He also notes that he cannot discuss what anyone said during the dinner in order to maintain their privacy. 

Johnson has hosted biweekly “Don’t Die” dinners for the last few years, and has welcomed hundreds of guests—including politicians, astronauts, artists, and scientists, he says. Johnson says the impetus for the dinners is to provoke conversations about what it means to be human. “Don’t Die” is “the punchline of the dinner,” he says. 

He tries to embody the phrase everyday by doing everything he can to optimize his health.

“For me to even begin to imagine that I get to predict my life expectancy would be insane. We can’t see past a year, two, or three years,” he says. “The only thing I do know is we need to build systems that don’t die as a society.” 

The food served at the dinner is what Johnson eats daily, which is designed by his team of doctors who help curate his Blueprint—a specific lifestyle plan and regimen for exercise, supplements, and more. 

Johnson says he begins every ‘Don’t Die’ dinner with two questions. 

“I say, if you had access to an algorithm that can give you the best physical, mental, and spiritual health of your life, but in exchange for access to the algorithm, you would have to go to bed when it said, and you would exercise in the way it said, would you say yes or would you say no?” 

Next, he asks people to think about the 25th century and how future people will think about the morals, ethics, and norms of today. “The next question invites introspection and contemplation of who we are in this moment,” he says. 

The Kardashian family, known for their beauty brands, have been eager adopters of new technology aimed at keeping their insides as healthy as their exteriors. They’re part of the trend of wealthy longevity enthusiasts who are buying and promoting subscriptions and tests that claim to indicate how well you are aging or promise longer lifespans. Kim Kardashian was among the first supporters of Prenuvo’s full-body MRI scan, which aims to spot early signs of disease, sharing the experience with her over 360 million Instagram followers. 

While a dinner over nutty pudding and longevity-themed conversation is harmless, critics have posed concerns about Johnson’s methods and about the emerging field of longevity science. 

Whole-body MRI’s, for example, are not recommended by the American Academy of Radiology for preventative purposes as there is insufficient evidence to back up their efficacy. The longevity science field is also fairly new, and experts have cautioned that some longevity science is just pseudoscience.

Johnson has come under fire for experimenting with approaches not FDA approved like swapping blood with his teenage son. Still, he is all in on the mindset of biohacking his way to a longer life and says he does not promote his $333-a-month Blueprint protocol at the dinners (although anyone is welcome to sign up). 

“‘Don’t Die’ is the most commonly played game by every human on the planet,” Johnson says. “As a species, we love games. I think ‘Don’t Die’ could basically be the next game we play.”