An entrepreneur has revealed the secrets of success of the world's rich and famous - and it's all to do with what they eat and drink.
Tim Ferriss, 39, who is himself worth about $20 million, interviewed nearly 200 CEOs, and other business moguls for his new book, Tools of Titans, which exposes the habits, routines and tactics of 'billionaires, icons and world class performers'.
And many of them said it was their very specific eating habits that gave them the energy and drive to earn their riches.
Some of the diet tricks are easy to replicate - but others will require some investment and a hunt for obscure ingredients.
For Ferriss, the bestselling New York author of The 4-Hour Work Week, his top tip is to drink 'Titanium Tea' - a blend of his own creation.
The tea is a mix of the aged black tea Pu'er, longjing or dragonwell green tea, coconut oil as well as a concentrated MCT oil (which stands for medium-chain triglycerides, a form of fatty acids) and a blend of turmeric and ginger.
Ferriss likens the tea's smell to 'a wet horse's a**' but says it is 'rocket fuel for the brain'.
He told Thrillist: 'The fat loss and energetic benefits consistently blows me away.'
When Ferriss interviewed bestselling author, public speaker and entrepreneur Seth Godin, it was revealed that Godin eats the same thing for breakfast every single day.
For a man who managed to start up two new businesses while writing his self-help books, Godin said having the same meal everyday saved him valuable time as it's 'one more decision I don't [have to] make'.
And his breakfast of choice is a smoothie of frozen bananas, hemp powder, almond milk, dried plums, and walnuts.
Ferriss, who also has a successful podcast, also reveals that despite busy schedules and working all hours, the world's most successful tend not to drink coffee for an energy boost.
He says you don't have to cut it out all together - but that if you find you have more than four cups a day, try switching to matcha or green tea instead.
The bizarre sounding goat whey protein was another food item that Ferriss reveals is also the key to his success.
This protein from goats can be bought in powder form - and added to smoothies and other drinks.
'Goat whey protein, which sounds horrifically gross, is actually very innocuous,' Ferriss told Thrillist. 'It was recommended to me by Charles Poliquin, a famed strength coach, who's worked with Olympic medalists in more than 20 sports.'
Ferriss also recommends consuming plenty of exogenous ketones - a dietary supplement - if you want to be successful.
Ketones are a fuel source and an alternative to glucose. 'You can mix up a cocktail that tastes like lemonade,' Ferriss told Thrillist. 'The brain and heart, among others, love ketones as an alternate fuel source.'
Billionaires need sleep just like the rest of us - but insomnia can be a problem among the rich and famous.
Ferriss said he was taught a clever trick to cure sleeplessness with one simple recipe by the late Seth Roberts, a professor emeritus at Berkeley University.
He advises insomniacs to mix two tablespoons of apple cider vinegar, with one tablespoon of honey into hot water - and says it has worked for 'thousands' of his fans.