Rob Kardashian has checked himself into rehab

A source said: "Rob is in good spirits and has a positive mindset. He quietly checked into a beachside Palm Beach County drug and alcohol in-patient rehab center over the weekend."

Celebrity bodyguard and local resident Mark Behar - a friend of Rob and his sister Kim Kardashian West - went on to say that he spoke to Rob just before he checked himself in, and thinks he'll lose between

10 and 20 lbs within weeks.

Speaking to Gossip Extra, he said: "He told me, 'This is it, I just need to stick with it and do this. His regiment includes weight loss and physical training. Rob will probably lose 10 to 20 pounds within the first few weeks by just being in rehab and daily programs relating to his detox."

Season 10 of 'Keeping Up The Kardashians' began in March with an episode showing the family's concern for the ex-boyfriend of Rita Ora.

At the time, Rob's mother Kris Jenner said: "If I don't help him do something drastic, he's going to die. He was someone who was very athletic and he's gained over 100 pounds in the last year. I'm just waiting for this horrible thing to happen and there's nothing we can do about it."