In an episode of Keeping Up With The Kardashians which aired in the US this week, viewers saw Kim dishing out some tough love to her younger sibling.
Kim, 33, spoke out after Rob, 27, didn't turn up for the family's planned holiday to Thailand earlier this year.
"We've all been here to offer him help and he won't take it, so I don't have sympathy. I think I'm just more of the tough love kind of person. My personality is, 'All right, you complain, you don't like it, get up and do something about it.'"
Tough love, indeed.
Rob's other sister Khloe, 30, however, was on his side, saying he had "deeper issues than just weight", including the fact he was missing Lamar Odom, her estranged husband. Rob and Lamar had been firm friends while Khloe and Lamar were together, especially as Rob had been living with them at their marital home.
Khloe felt bad about getting on the flight to Thailand without knowing why Rob hadn't turned up. He was ignoring her messages, but she ended up getting on the flight anyway.
Later in the year, concern was sparked when Rob skipped Kim's wedding to Kanye West in Florence, Italy,
Although Rob flew out to France for the pre-wedding celebrations, he was seen boarding a flight back to LA on 25 May, the same day Kim and Kanye tied the knot.
The following month, his mum Kris Jenner confirmed that Rob was "struggling with some stuff" but declined to reveal any specific details.
"Rob is working on himself," she told Today. "He's going to be okay. He's such a great human being and such a nice boy. He's my heart."
Kris later told E! News: "Rob is living in LA right now and doing well. He's finding out what makes him tick and struggling with some stuff. My job is to be there for him and love him as hard as I can. Everybody goes through stuff."
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