Kim Kardashian hit the beach in Miami last week, sporting a slim body in her bikini. Workout regimen? Nope, her new “sex diet.”

According to the Daily Mail, her trim figure is the result of her active sex life with boyfriend Kanye West.

One friend reportedly 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.”