Kim Kardashian’s latest get in shape plan is an invention all of her own – the “sex diet”.

As Kim Kardashian showed off her beach ready curves in Miami it emerged that she had honed them with the help of boyfriend Kanye West.

A close friend told the National Enquirer: “We jokingly refer to it as the sex diet. When one of us is having regular sex, that tends to burn calories and kill the appetite.

“Losing seven pounds in seven days means being a very naughty girl.”

Kim Kardashian showed off her beach ready curves in Miami

Kim Kardashian, 31, showed the results of her special workout as she stepped onto the beach in Malibu last week.

With her publicicst friend Jonathan Cheban at her side, Kim Kardashian walked in a black sarong, tied over a black and bright orange strappy bikini.

Kim Kardashian then shed the sarong for a dip in the azure waves, with Jonathan Cheban holding her belongings as he waited on shore. After her dip she showed him a few workout moves, doing some stretches on the beach.

Kim Kardashian’s weight has fluctuated over the years, with the petite 31-year-old oscillating between a gym honed taught figure and her more natural curvy shape.

Recent pictures of her in form fitting outfits have sparked speculation that she has added weight to her curves.

And according to the source that is just what she is aiming for.

“Kanye loves her curves and has told her repeatedly that she shouldn’t get too skinny,” they said.

“He’s always encouraging her just to be happy and healthy and do things for herself and not give in to peer pressure, which is why he doesn’t think she should lose weight.

“Kim was speechless, especially when he told her he missed her love handles. Kanye can’t understand why she has lost weight when she knows it’s not the look he likes.

“He thinks Kim should be doing everything to please him – not herself.”