"The bulimia started the week after we got engaged (and would take nearly a decade to overcome)"

By Karen Mizoguchi
June 09, 2017 08:52 PM

Diana: Her True Story – in Her Own Words is being republished later this month with a new foreword from author Andrew Morton, timed to the 20th anniversary of Princess Diana’s death in August.

The late Princess of Wales herself was the secret “source” for the book originally, speaking through tapes given to Morton by her friend, James Colthurst. The truth of Diana’s involvement came out after her death — including her private battle with bulimia nervosa: the binge-and-purge syndrome that afflicts millions of women.

“The bulimia started the week after we got engaged (and would take nearly a decade to overcome),” Diana had recorded herself saying. “My husband [Prince Charles] 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.”

Diana was referring to Camilla Bowles‘ relationship with the Prince of Wales, an affair that occurred while she was still married to her first husband Andrew Parker-Bowles and Charles was still married to Diana.

RELATED VIDEO: Five Things To Know About Princess Diana and Prince Charles’ Strained Relationship

“I was desperate, desperate. I remember the first time I made myself sick. I was so thrilled because I thought this was the release of tension,” Diana continued about her illness.

“The first time I was measured for my wedding dress, I was 29 inches around the waist. The day I got married, I was 23½ inches. I had shrunk into nothing from February to July. I had shrunk to nothing,” she said.

In his book Diana: Her True Story (which was excerpted in PEOPLE in 1992), Morton asserted: “I think she slimmed before the wedding as a result of nerves, and then the whole thing was triggered during her honeymoon, when her husband put his arms round her and said, ‘You are a bit chubby, darling.’ ”

Morton also wrote that Diana’s struggle may have had an ironic benefit as painful as it may have been.

“Having suffered much, she is now able to empathize with those who suffer far more,” he said. “Whatever happens to her personally, it must be heartening for her to know that thousands of women have gone for help as a result of the publicity.”