The 26-year-old reality star was pictured in Las Vegas after a diet and exercisee plan in February. He was noticeably thinner.

Rob Kardashian claims at the event, "I still have to lose like 40 to 50 pounds believe it or not. Six months I should be there."

The man clad in a suit and sunglasses was celebrating the launch of his new "Arthur George by Rob Kardashian" socks.

The hardcore twice a day workouts with him and his friends was "too much." But he had also been training with personal trainer Lamar Odom, to achieve the weight loss.

In the February episode of the popular tv series Kourtney & Kim Take Miami, he claimed that he gained weight because of splitting up with Rita Ora, saying "All I did was gain f***ing 40 pounds and lose so much money."

Khloe Kardashian has recently also shown signs of weight loss at her sister Kim's house on Friday. The expecting 32-year-old Kim gained over 60 pounds in the past 7 months. The media has been using that weight gain as a source of ridicule.

Rumors have been circling that the jealous sister Khloe is trying to take the place of the popular Kim. Will this sibling rivalry arise a twin of equal hotness? That remains to be seen.