Rob Kardashian's family are staging an ''intervention''.

His mother Kris Jenner and sisters Kourtney, Khloe and Kim Kardashian are reportedly planning to help the troubled 28-year-old star get help.

A source told US' OK! magazine: ''[He's] a heart attack waiting to happen. Kim, Kourt and Khloe have united with Kris to finally get Rob the help he needs - whether he wants it or not.

''[They're] so done with his excuses and aggression ... [They want to] force him into a weight loss rehab centre.''

Meanwhile, Kim recently admitted she thinks brother Rob ''smokes weed'' all day.

The 34-year-old beauty said: ''It's not that mysterious, what's happening with Rob. He has gained weight. He feels uncomfortable being on the show, and that's OK.

''Do I think he smokes weed, drinks beer, hangs out and plays video games with his friends all day long? Yes.''

A source also previously claimed the family are ''worried sick'' about Rob's social anxiety.

They said: ''Rob has extreme social anxiety, is very unhealthy and just isn't doing anything to get back on his feet.

''The whole Kardashian and Jenner family is worried sick about him but they just don't know what to do.''