Kim's weight loss plan equals lots of sex, one report claims.

Can Kim Kardashian help her sister Kourtney Kardashian with some weight loss tips after giving birth to baby Penelope Scotland?

Kourtney bounced back into shape quickly after her first child Mason was born, so the beautiful brunette mom may not need any help after baby number two, but just in case, a report claims that Kim has discovered lots of sweaty sex can peel off the pounds.

A report claims Kim Kardashian lost 7lbs by having lots of sex with Kanye West.

The curvy reality TV star recently lost weight in a very quick period and family sources believe it was down to the fact she enjoyed a lot of intimate time with her rapper boyfriend.

One told National Enquirer magazine: ''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."

However, Kanye is reportedly not impressed with Kim's new figure as he prefers her when she has more curves.

The source added: ''Kanye loves her curves and has told her repeatedly that she shouldn't get too skinny. 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.''

(Image: WENN)