Rob Kardashian's weight gain has affected him emotionally.

The extra pounds even forced the youngest Kardashian to skip out on a family vacation in Greece. The trip was documented on the family's reality show, Keeping Up With The Kardashians.

"I was not feeling myself like gaining a bunch of weight," he explained to Lamar Odom in a scene from the show. "It's just frustrating to me that I'm not happy going out if I'm not in good shape. Within the next six months, if I don't get this together then I won't want to hang around everybody."

Celebrity Weight Loss Photos That Will Shock You

Kardashian has been working hard to shed the pounds. He recently lost a bit of weight but still has a long way to go.

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

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At the time, he said that he plans to lose all the weight he gained by working with the same personal trainer Odom has.

Scroll through our gallery to see photos of Rob before and after.