Rob Kardashian hopes to lose 50 pounds in six months.

The 'Keeping Up With The Kardashians' star - who has been struggling with his weight ever since breaking up with singer Rita Ora last December - was initially trying to get down to his goal weight before July 4 by sticking to a low-carb diet but admits it is more difficult than he thought it would be.

The 26-year-old reality TV star told UsMagzine.com: ''I still have to lose like 40 to 50 pounds believe it or not. Six months I should be there.''

Rob, who tipped the scales at 235 pounds in March, revealed he has scaled back on his twice-a-day workouts but is still exercising regularly with his brother-in-law Lamar Odom's trainer.

He said: ''That got [to be] too much . . . we do that, but I'm kind of doing my own thing with Lamar [Odom]'s trainer. He's on salary since he was 19 years old, so he works for us. I've been spending time with him.''

He is determined to get fit and healthy by watching what he eats and cutting back on alcoholic beverages.

He explained: ''I'm not really drinking out here in Vegas -- 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.''

Rob confessed last month the breaking point came when he became upset by how his naked body looked when he took a shower.

He sighed: ''Every time I hop in the shower and see myself naked I cry, because my penis looks so small. The upside is, every time you lose 10 lbs. you gain an inch on your penis.''

Rob recently pled ''not guilty'' after being charged with attacking a female photographer in March, who tried to take a picture of him with no shirt on, and is facing a trial for misdemeanour battery and petty theft.