Rob Kardashian weight loss update: Kim Kardashian's brother looks slimmer in first selfie after 100-lb weight gain

Rob Kardashian posted a selfie on Instagram after being a recluse for many months. In his photo, he looked thinner and healthier than the last time he was seen in public.

In a report by People, Rob has resurfaced after staying away from the public eye for many months. The magazine added that Kardashian suffered from depression and gained more than 100 pounds.

On his Instagram, Rob captioned a black and white photo of his much slimmer face with "Gnight." This suggests that Rob's workout session with sister, Kim Kardashian-West, has done him good.

According to US Magazine, Rob has been active on his social media recently. He updates his accounts with photos and tweets about exercising. Likewise, Kim K has also shared their fitness habits together on her own social media accounts as well.

Kardashian also showed off his sense of humor on his Instagram. He shared an old photo of him sipping on a milkshake. He humoredly captioned the snap with: "Started right here with these milkshakes hahaha #throwback Thursday."

A source close to the reality star told E! Online that he has also been working out with his personal trainer, Gunnar Peterson.

"His regimen involves more than just cardio and weights," the source told the website. For his diet, Rob is allegedly "working with a chef and doing really well."

The Daily Mail reports that Kardashian's weight ballooned after breaking up with his ex-girlfriend Rita Ora in 2012. After living alone, he moved to his sister Khloe's Calabasas mansion.

"Rob lives with me now and I wouldn't have it any other way. I love having him with me," Khloe said, according to the outlet's report. "I have a big ass house and I wanted it so he could feel, like, comfortable."

Khloe also told E! about his brother's path to recovering from tough times.

"Right now I'm really proud of him. He's been working out a little and trying to get his groove back," said Khloe. "And he acknowledges it! He's aware that he's very introverted and of course not the way he used to be. I think being aware is probably the best thing."

Meanwhile his mum, Kris Jenner told ET Online about Rob's condition.

"He's doing terrific. Robert's good. He's working out and eating [well], so he's on a good path right now," Jenner told the outlet.