By Bianca Tan (staff@latinospost.com) | First Posted: May 27, 2013 03:24 PM EDT

Rob Kardashian is taking his weight seriously. On Saturday, May 25, the reality TV star showed off a slimmer body as he stepped out for the launch of his new sock line "Arthur George" by Rob Kardashian, at Neiman Marcus in Las Vegas.

Rob, the only boy in the Kardashian clan, has been working on losing weight since February following his split with former girlfriend, Rita Ora.

"It's crazy how this whole year, my whole relationship was only negative. All I did was gain [expletive] 40 pounds and lose so much money," the former Dancing With the Stars contestant.

In March, Rob told Us Magazine that he weighed over 235 pounds. However, since then, the star has been on a strict diet and exercise routine to shed the unwanted pounds. He also took on the services of his brother-in-law and LA Clippers star, Lamar Odom's trainer.

Talking about his former 200 plus-pound figure, he tells Us Magazine, "That got [to be] too much...we do that, but I'm kind of doing my own thing with Lamar's trainer. He's on salary since he was 19 years old, so he works for us. I've been spending time with him."

The Keeping Up with the Kardashians star also revealed that in line with his efforts to lose weight, he has ditched drinking.

"I'm not really drinking out here in Vegas," Kardashian told Us. "I've been here since Wednesday and I leave Monday--that's way too long. But I'm trying to get in a healthy direction," he added.

The star has been very serious with his weight loss journey, and so far he has been successful with it. But Rob says he still needs to shed more pounds.

"I still have to lose like 40 to 50 pounds believe it or not," he told Us. "Six months I should be there."