Rihanna reportedly wants rumoured boyfriend American actor/film producer Leonardo DiCaprio to follow a strict diet and get into shape.

In July 2014, Daily Mail had published photos of the Titanic star on a beach in Miami, looking considerably heavier.

According to OK! Magazine, the Diamonds singer is not happy with the 40-year-old Wolf Of Wall Street star's current physique.

"Ri's got extremely high standards when it comes to who she sleeps with and Leo falls out of this category because he's a lot more flabbier than her usual lovers," a source said.

However, DiCaprio has not realised Rihanna's hint that he should lose some weight.

"Leo thinks it's all highly amusing," the insider said. "He's never had a girl tell him what to do, so you can imagine how much he's loving it."

"She wants him to get a six-pack," the source added.

Chris Brown's former girlfriend and DiCaprio have been spending a lot of time together and are getting serious about their relationship.

Hollywood Life recently reported that the We Found Love singer made the actor a big promise about her body that totally "blew her mind".

"Rihanna has always been the type of girl who does whatever she wants, when she wants. She wants a new tattoo on her body, but she's stuck because Leo asked her to promise him she won't let the needle touch her body until she falls in love again. She's a woman of her word and she's sticking to that," a source told the website.

"He wasn't possessive and that blew her mind," the insider added. "She thinks he's playing some type of mind game with her and she's intrigued by it. Rihanna loves a challenge, and he's unlike the dudes in her past, those were boys. This is Leo, he's something else. He's hitting all the right spots and I'm not talking between her legs. He's making her feel good and stimulating her on an entirely different level."