It was June, four years ago, when Kenton first contemplated writing about her childhood and "Love Affair" gives full extent of the horrors and the secret incest at its heart, dailymial.co.uk reports.
"My friend Gail Rebuck, who was my first editor and is now the chairman of Random House, told me, 'You need to write a memoir.' I said, 'Gail, I can't. No one would believe it, and the tabloids would go wild.' And Gail said, 'Who cares? This book will be the bridge between what you have done before and the work you will do afterwards.'"
For decades, there have been hints that the woman known as the high priestess of the real beauty movement - she advocated high-raw, high-vegetable diets and detoxifying way back in the 70s, created the Origins range and imported the skincare tablet Imedeen to Britain - had built her luminous present from a murkier past.
Talking about the book, Kenton said: "It ripped me to shreds".
The book reveals that during the summer of 1952, Kenton met her father Stanley on tour, sharing his hotel room, sleeping back to back. While touring with his dance band, he was drinking heavily and Kenton who was just 10 was trying to police her dad. He was, in many ways, treating her as a substitute for his wife Violet. One night the final boundary was crossed and he raped his daughter. It was the beginning of an incestuous relationship that lasted until she was 13.
During visits, the days were as sunny as ever. They shared a unique exhilaration when together. Some nights he left her alone.
"I believe he tried his best to resist touching me. Then, drowning in a sea of alcohol, he would come to my bed, only to deny the next morning that he'd been there. This was not cynical. Stanley had become so skilled in keeping secrets he could hide his guiltiest one even from himself.
"He was born into guilt. As a child, he was taught by his mother, 'There's something wrong with you, Stanley.' From talking to relatives, Leslie has learnt of a highly dysfunctional family with a history of manipulation, neglect and bizarre cult-like rituals.
"I do not know how to express the damage that a family like this does. This is a disease that's passed on. Some people survive it and others are deeply damaged."
Kenton thinks her father experienced a condition known as dissociative identity disorder, involving selective amnesia, which she also developed as she blocked out the incest.
While working on the book, Kenton retreated to her rambling house perched atop an extinct volcano on New Zealand's South Island.
"Love Affair" is dedicated to her father - 'For Stanley, with all my love' - a tribute as startling as it is sincere.
