Ashton Kutcher became seriously ill after copying Steve Jobs' diet.
The 35-year-old actor was rushed to hospital with severe pancreatic pain when he adopted the late Apple founder's fruit diet, based on the 1922 book 'Mucusless Diet Healing System' by Arnold Ehret, in order to get into character as the computer whizz for new biopic 'Jobs'.
Ashton "started consuming the things that [Jobs] admired", only to realise the business tycoon - who passed away in October 2011 from pancreatic cancer - had been following a "misinformed" method.
According to MailOnline, he told reporters: "[The book] talked about the value of grape sugar and that was probably the only pure sugar you could have in your body.
"I think the guy who wrote that book was pretty misinformed. My insulin levels got pretty messed up and my pancreas kind of went into some crazy, the levels were really off and it was painful. I didn't know what was wrong."
The 'Two and a Half Men' funnyman defended the entrepreneur's leadership style, saying he understands why he may have seemed "blunt" with his employees.
Ashton explained: "There were some things that Steve Jobs' approach seemed very blunt and unkind. However, it was that same blunt discernment that allowed him to create the amazing products he created."
The actor - who is dating his 'That 70's Show' co-star Mila Kunis - revealed he also got into character by listening to Jobs' favourite music and even wearing the same shoes as him.
He laughed: "He'd go for a walk when he wanted to have a meeting with someone and I just started doing that and started walking without shoes on and wearing Birkenstocks and going for one-hour walks every day."