Lamar Odom appears to have put on weight.

Is Lamar Odom Returning To 'KUWTK' This Season?

In photos of the former NBA star heading to New York from Los Angeles, Odom was seen looking a bit larger than he's been in the past. In addition, a source claimed he's drinking again -- and allegedly using drugs.

“Lamar had two shots of vodka and he told the flight attendant ‘Vodka and Xanax and I should wake up there,'” an eyewitness told Radar Online on Tuesday. “And he was talking on the phone and told that person that he took Xanax and took two shots.”

Lamar Odom's Friend Jamie, A 'KUWTK' Guest Star, Has Died Of A Heroin Overdose

“He went to the bathroom three times. He jumped up as soon as the seatbelt light went off and went straight to the bathroom," the source contiued. "It was a really bumpy flight and a flight attendant asked if he could make it back to his seat or if he wanted to use their jump seat. He didn’t sit there; he just kept playing with the seat, pushing it up and down and laughing.”

According to a report by E! News on Monday, Odom and Sangouthai "haven't spoken for a year," but the former basketball player was still "very shaken up" by the news of his friend's reported drug overdose.

"It's very scary when someone you know so well dies suddenly," an insider close to Odom told the site. "It's been a wake-up call for Lamar as he realizes that he could personally be in a very different place if he was still as close to Jamie."