Is Rob Kardashian battling fat with basketball player Lamar Odom? Khloe Kardashian's ex reconnected with the "Keeping Up with the Kardashians" star and sock mogul amid the growing concerns from his weight gain.

Rob Kardashian's weight gain has been a source of burden not just for the "Keeping Up with the Kardashian" reality star but also with the rest of the family, particularly momager Kris Jenner who has reportedly been very harsh about Rob Kardashian's battle with fat.

A source told Radar Online that Rob Kardashian's weight gain could be partly tied to the split between Lamar Odom and Khloe Kardashian.

"It was extremely hard for Rob when Lamar and Khloe split because first and foremost, he hated what it did to Khloé," the source said.

But the separation and the ensuing divorce papers that Khloe Kardashian filed before the Los Angeles court "essentially had ended Rob and Lamar's relationship....they called each other brother, and meant it. There was a lot of love there."

The good news, however, is that Lamar Odom is reaching out to help Rob Kardashian battle fat.

"Within the last few weeks, Rob has reconnected with Lamar," the source added, explaining that the timeline coincided with when Lamar Odom also reconnected with Khloe Kardashian.

"Lamar asked her if it was ok if he reached out to Rob, and of course, she said yes. No matter what happens with them in the future as a couple, Khloé wants her brother and Lamar to maintain their friendship," the source told Radar.

Rob Kardashian's weight gain woes were apparently splashed all over Twitter when he wrote last week: "no one will ever understand how much it hurts."

The Star earlier reported that Kris Jenner has been very harsh of her criticisms over Rob Kardashian's weight gain.

 "She called him a fat slob and said he's losing out on business opportunities because no one wants someone as huge as him representing their products," the source told Star.