The actor and comedian, 66, has been open about his struggles with drugs and mental health issues in the past.
Fry told John Cleese's The Dinosaur Hour on GB News: "When I was a teenager, I had this vast empty hole in me that said'Feed me, I need this sugar, I need it'.
"When it wasn't sugar, it became tobacco, so I smoked and then in my twenties it became cocaine. I just couldn't sit still. It's that addictive impulse."
He also cited TV adverts for sugary cereals and other food, along with his boarding school's tuckshop, having sherbet as the reason he had the opportunity to develop the addiction.
Fry added: "They (the tuckshop) even, extraordinarily, had ... rolling tobacco, which was coconut shreds, but it was done exactly like a rolling tobacco packet.
"You would have a pipe made of liquorice and you would have cigarettes with red tips on the end, which were candy cigarettes.
"So, you were being prepared for cocaine and tobacco. Essentially you were given white powder and tobacco and I never could eat enough of that.
"I would break out of school and go to the village shop. I couldn't eat them quickly enough."
However, the former host of the popular quiz QI who was nominated for a 1999 Golden Globe for his performance in biopic Wilde, said his "addictive" personality does not extend to his relationship with alcohol.
Fry said: "I do like a drink, I like wine, but I know I could never be an alcoholic. I just don't like it enough. I don't like feeling sick.
"I don't like having to cope with the responsibility of apologising the next day if I've been drunk. I don't like the fact I might get a bit argumentative. So I could never be an alcoholic."
Elsewhere, Fry - also known for his long-term partnership with Hugh Laurie on comedy sketches and TV series Jeeves And Wooster - spoke about tech entrepreneurs running social media websites.
He said: "They were making huge sums of money out of it, they were inventing new ideas, and they were sweeping away everything from the past and the betrayal to me, the hypocrisy, is that somehow we believed in the nineties and early 2000s these guys in jeans and T-shirts were gentle, sweet people who wanted the world to be better.
"We now know that, in Orwell's magnificent image, the pigs are now wearing trousers."
In the political satire, Animal Farm by George Orwell, the pigs take over after the farmer is deposed.
Fawlty Towers star Cleese debuted his new program, filmed inside 12th century Hedingham Castle in Essex, on GB News last month.
Media personality Caitlyn Jenner, journalist Sir Trevor McDonald and former Who Wants To Be A Millionaire host Chris Tarrant are also among his guests on the 10-part series.
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