"That was almost a relief, because then he can take all the steps," Jenner said. "It was like a godsend, so it's all good. It's one thing to say, 'Oh, I'm going to get on the healthy path,' but then you really need to get on the healthy path."
"Rob has been to that happy place before in his life," she added. "He's such a perfectionist. It's a big challenge for him now to turn all that around, but he can, and that's the good news, is he can turn it around and be in a much healthier place."
Rob Kardashian gained 100 pounds in the past three years, and has largely retreated from the spotlight. His sister Khloe has been a strong support system in his seclusion, and Jenner said she also leans on her 31-year-old daughter.
"It makes me want to be a better person when I'm with Khloe, and I think she has that effect on a lot of people," she said.
"She's an amazing girl who has so much to offer and give on so many levels, and that's why she's so good with everybody, you know, and she's focused on helping other people, especially in my family, get well."
Khloe Kardashian suggested this week her brother's issues started with their dad's death on "Watch What Happens Live." The reality star is also caring for estranged husband Lamar Odom, and responded to backlash about her dating life on the "Kocktails with Khloe" premiere Wednesday.
"Kendall is the smart one -- she moved across town," she joked. "For me every one of my kids now has their own place, which is such a blessing. I never thought I would be in this place where all your kids are taken care of and settled down and have a home, and that's such a joy for a mom."
Jenner and her family continue to star on the E! series "Keeping Up with the Kardashians," which airs Sundays at 9 p.m. ET. The reality star finalized her divorce from Caitlyn Jenner in December, and is presently dating talent manager Corey Gamble.
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