Bryan also said that he grew up in 'typically American' and 'not healthy' way where he ate many sugary cereals, but now eats zero cane sugar because it has 'no benefits'.
'We're baby steps away from creating super intelligence, we cannot model out what the future is like in any way, shape or form,' he explained.
'The only thing we can play is don't die, don't kill each other. And don't underestimate AI.'
Discussing his diet, Bryan said he eats 2250 calories a day and 'every calorie has to fight for its life'.
He starts his day with a bowl of 'super veggies' which includes broccoli, cauliflower, garlic, ginger, and hemp seeds with extra virgin olive oil and cacao. He doesn't add any salt or seasoning except potassium chloride.
Eating around a kilogram of vegetables a day, he says that he adds dark chocolate to put off any sweet cravings.
He then has a 'dessert' of macadamia nuts mixed with berries and proteins.
Three tablespoons of extra virgin olive oil, as well as a drink of 'green giant' are also part of the diet as well as 111 pills.
Bryan spends $2million (£1.6m) a year on a team of more than 30 doctors and medical experts that oversee and test almost every one of his organs. Their aim is to engineer his body into that of an 18-year-old.
He has taken 33,537 images of his bowels and monitors everything from his bone weight to his number of nighttime erections.
He and his doctors claim that in two years he has reduced his overall biological age by more than five years and now has the heart of a 37-year-old, the skin of a 28-year-old, and the lung capacity and fitness of an 18-year-old. His medical team is led by Oliver Zolman, a 29-year-old doctor researching aging therapies in Cambridge.
In his 30s, the entrepreneur founded Braintree Payment Solutions, a hugely successful company that he sold in 2013 for $800million.