The 29-year-old 2003 Miss World winner will feature in the magazine's September issue, following her German Playboy debut, where she appeared naked in its September 2012 edition.
It seems Playboy veteran Hugh Hefner requested to re-use her original German Playboy feature, so there was 'no pressure to get into shape,' Miss Davison told The Herald.
Rosanna Davison: The daughter of British singer Chris de Burgh and 2003 Miss World winner is set to become the first ever Miss World to feature in U.S. Playboy
'The shoot I did for Germany was just after January,' she explained. 'I had to have a super-healthy Christmas. I had to drink nothing but water – it was all very sad.'
In this week’s column for The Sun, she admitted that while shooting Playboy a second time around would have been less 'nerve-wracking,' she was ultimately pleased her Mauritius beach shots were re-used.
'I was in control of every aspect of [the German] shoot and I may not have been given such freedom and choice with a new shoot,' she explained.
Miss Davison, said she received a call from her manager in October 2012 to say that Hefner had been in touch to express his interest in meeting her.
Beach-side shoot: The 29-year-old will feature in the magazine's September issue, following her German Playboy debut, where she appeared naked in its September 2012 edition
But due to work and study commitments, she was unable to travel to Los Angeles until the following May.
'Driving up to the Playboy Mansion was simply surreal,' she gushed.
'We were made to feel welcome there, with pre-dinner drinks, a tour of the house and gardens, a sit-down dinner with Hugh and his wife Crystal and a Charlie Chaplin movie in his own home cinema.'
The University College of Dublin graduate said she loved having 'a nose' around the famous mansion.
Miss World: The model, who won her Miss World crown a decade ago, said she received a call from her manager in October 2012 to say that Hefner had been in touch to express his interest in meeting her
'It was just like heading to a mate’s house for dinner and a movie!' she joked.
Despite the grueling diet, former Miss Ireland admitted she is glad she'll have the pictures to look back on, 'when I’m old and grey,' she said.
'Ultimately, I’m proud of myself for pushing my own boundaries.'