But in the new issue of People magazine, the 29-year-old Keeping Up With The Kardashians star revealed that he actually gained several of those pounds back.
The fiance of Blac Chyna was unusually candid as he broke down the numbers, admitting he was 300 pounds at his peak, had lost 30 pounds, then gained 20 back. He is now 285 pounds.
He also said that he no longer has diabetes thanks to Chyna's home cooking.
'I dropped 30 pounds really quickly,' he said after Chyna put him on a diet in January.
'But I gained about 20 pounds back. So now I am in that uncomfortable state again. I weigh 285 pounds now. I've got to get back into the routine.
'But it's hard because she's pregnant and eats whatever she wants, and I enjoy eating with her.
'Right now 210 pounds is my goal.'
Last year Rob was diagnosed with Type 2 Diabetes. In December he had to go to the hospital.
'It was a big-time scare. I had found out I had Type 2 diabetes six months before but I stopped taking my insulin,' he said.
'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 knew I needed to make changes.
'Chyna and I had a really big talk and and she told me that by having her cook for me, my diabetes would be gone. And it is.'