The 'Keeping Up With the Kardashians' star has reportedly ballooned to 300lbs since he and the 29-year-old model - who is the mother of his nine-month-old daughter Dream - split earlier this year and friends are concerned about his health.
A source explained: ''He's the biggest he's ever been. He's well over 300lbs now - we don't know as the scales don't go up past that - and he's a heart attack waiting to happen. He's been comfort eating big time. His fridge has become his best friend.''
The 30-year-old sock designer - who was diagnosed with diabetes in 2015 after he piled on the pounds - has reportedly been binge-eating on fast food and candy and gulping down cans of soda.
An insider told RadarOnline: ''He's got major anger and addiction issues, brought on by a chronic lack of self-esteem over his looks and his position in the family.
''He's lost the will to live and if it wasn't for his little girl he'd probably not have made it.''
Rob previously credited Chyna as his ''motivation'' for losing weight after they started dating last year.
Posting a picture of them on Instagram previously, he wrote: ''Looking from where I started 298lbs to my current weight now 248.4lbs. I'm focused and determined to reach my goal weight 200-205lbs .... Happy I found my motivation.''
He also claimed his then-partner had helped him beat diabetes with her loving home cooking.
Speaking after being hospitalised with the condition, he said: ''It was a big-time scare. I had found out I had type two diabetes six months before but I stopped taking my insulin. I didn't enjoy the routine. So I ended up nonstop throwing up, and I couldn't even swallow because my mouth was dry. I felt like I was going to die. When I got out of the hospital, I knew I needed to make changes. Chyna and I had a really big talk and she told me that by having her cook for me, my diabetes would be gone. And it is.''
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