Almost three decades on since the world was forced to bid a tragic farewell to the late Princess Diana, her former dance teacher, Anne Allan, has lifted the lid on on the royal’s battle with bulimia in her new book Dancing With Diana.

According to a Wednesday, September 4, excerpt in People, Diana had confided in Allen about her struggles with bulimia.

“Her head dropped and, unable to look me in the eye, she said, ‘I am so ashamed, Anne, but I need to tell you that I suffer from bulimia,’” Allan wrote. “Her shame was evidently painful for her.”

As per her recollection, Diana profusely apologised for hiding her struggles “until now” as she opened up about how the illness had slowly been taking over her life.

“Diana explained that her bulimia had started when she had started attending important functions, particularly dinners where she had to sit down to eat,” Allan recalled. “Meeting so many people was terrifying to her and the feeling that she was being judged with every move she made or how she looked or what she said caused her to feel totally inadequate.”

“Understanding the disease was the way forward, I told her, adding that finding ways not to judge herself would come in time,” Allan wrote.

Diana first came clean about her battle back in 1992, while recording tapes for Andrew Morton’s bombshell biography about her life.

“The bulimia started the week after we got engaged and would take nearly a decade to overcome,” Diana had claimed in a recording. “My husband put his hand on my waistline and said: ‘Oh, a bit chubby here, aren’t we?’ and that triggered off something in me —and the Camilla thing.”

Three years later, Diana publicly confirmed her eating disorder during a 1995 interview on BBC’s Panorama.

“I had bulimia for a number of years. And that’s like a secret disease,” she recalled. “You inflict it upon yourself because your self-esteem is at a low ebb, and you don’t think you’re worthy or valuable. You fill your stomach up four or five times a day—some do it more — and it gives you a feeling of comfort. It’s like having a pair of arms around you, but it’s temporarily, temporary. Then you’re disgusted at the bloatedness of your stomach, and then you bring it all up again.”

During her years long battle with the brutal illness, Diana made the decision not to tell other members of the royal family about the situation as she felt ashamed of her actions.

“You have to know that when you have bulimia you’re very ashamed of yourself and you hate yourself — and people think you’re wasting food — so you don’t discuss it with people,” Diana said at the time. “The thing about bulimia is your weight always stays the same, whereas with anorexia you visibly shrink. So you can pretend the whole way through. There’s no proof.”

Princess Diana married King Charles back in 1981, when he was still the Prince of Wales. During their turbulent marriage, they welcomed two children Prince William and Prince Harry, but were later dogged by a heartbreaking scandal when it emerged that the now-King had embarked on an affair with his former lover (and now-wife) Queen Camilla. 

Clearly wounded by the betrayal, Diana eventually sought to separate from Charles and the couple officially divorced in 1996 - just one year before the Princess tragically died in a Paris car accident.

For more help and information on eating disorders, visit the Beat charity website.