Rob Kardashian Looks Noticeably Slimmer at Kim Kardashian's 39th Birthday Party

In a video posted to Kim’s Instagram Stories, a man who appears to be Rob can be seen walking along, appearing drastically slimmer.

Rob Kardashian stepped out for big sister, Kim Kardashian West’s, 39th birthday bash on Monday night and it seems the reality star may have dropped a significant amount of weight.

In a video posted to Kim’s Instagram Stories, a man who appears to be Rob can be seen walking ahead of his nieces, appearing slimmed down.

Rob, 32, also seems to be in the next segment of the video, sitting at a dining table with the clan, who enjoyed a home-cooked meal at Carousel Restaurant.

Rob’s continued efforts to improve his health and control his weight come after years of struggles, and in June, a source told ET that he was ”taking his health seriously and has been working out and eating better."

"Rob wants to be around as long as possible for his daughter, Dream, and in doing so, knew he needed to take control of his health," the source shared, noting that his efforts were proving successful.

"Rob has lost some weight, but has a long way to go," the source added.

Rob also documented his return to the gym with a tweet in June, writing, “Day 1 all good ????????,” alongside a photo of his view from the gym.

Later in June, ET caught up with Rob’s sister, Khloe Kardashian, and Kourtney Kardashian's ex, Scott Disick, who confirmed he was continuing to work out and prioritize his health.

"Rob is doing great. He really is," Khloe said. "You know, he's been working out.”

"He goes to Kim's, he's worked out for the past five days or so and he's kicking a**," she continued. "And, I just want Rob to do what's best for him and what makes him happy. And, if that makes him happy, then we will all support him."

See more on the clothing designer’s weight journey below.