Rob Kardashian has hired a private chef to help him lose weight.

The reclusive member of the reality TV family has seen his weight balloon over the past few years but the 28-year-old star, is now so committed to changing his lifestyle that he has hired someone to cook healthy meals for him.

A source told E! News: ''For the first time in a long time Rob is committed to changing his diet habits. He's been working with a chef and doing really well.''

Rob has also stepped up his exercise regime with his personal trainer Gunnar Peterson, with the source explaining: ''His regimen involves more than just cardio and weights.''

And Rob has even been joking about his weight gain, blaming it on milkshakes.

He posted a picture of himself from June 2011 enjoying the calorific treat on Instagram and wrote: ''Started right here with these milkshakes hahaha...#throwbackthursday.(sic)''

Meanwhile, Gunnar previously vowed Rob would be ''better than ever'' and was working hard.

He said: ''He's always in and out. He makes it work with his schedule and he's on his path. In the scheme of life this is a chapter, it's not 'The Book Of Rob.' Watch him be better than ever! Watch! I'm taking all bets!''

Over the past few weeks, the sock designer has been posting updates on social media about his workouts, revealing he had been hiking with his older sister Kim Kardashian and bumped into younger half-sister Kylie Jenner during a walk.

Rob is said to have piled on the pounds after overeating due to ''issues'' he and the family have faced.

An insider said: ''Food is Rob's vice right now and he is intent on beating this through whatever is necessary at this point. Rob's whole problem right now is that he is using food as his substitute to get over his issues.''