NEW YORK - Reality television star Kim Kardashian has defended her drastic diet to fit into the late Marilyn Monroe's slinky dress for the Met Gala in May.

Kardashian, 41, who is known for her curvaceous booty, came under criticism after she revealed to fashion magazine Vogue that she was so determined to wear the dress that she lost more than 7kg in three weeks by basically cutting out carbohydrates and sugar.

Defending her decision in an interview with The New York Times, she said: "To me, it was like, 'OK, Christian Bale can do it for a movie role and that is acceptable. Even Renee Zellweger gained weight for a role. It's all the same to me."

She added: "I wasn't saying, 'Hey everyone, why don't you go lose this weight in a short period of time?'"

The iconic gown, designed by Jean Louis, originally cost US$12,000 and was reportedly so tight that Monroe had to be sewn into it.

She performed in it for United States President John F. Kennedy on May 19, 1962, just three months before she died.

Ripley's Believe It or Not! purchased the dress on auction in 2016 for a whopping US$4.81 million, making it one of the most expensive dresses in the world.