Wess Schulze weighed in at more than 50 stone (700lb) when he appeared on My 600lb Life, but now looks completely unrecognisable after dropping five jean sizes.
The TLC reality star originally started to struggle with his weight during childhood, when he grew up associating huge portion sizes with his father's love.
Wess' parents divorced when he was three years old and his dad was given custody of his son because Wess' mother was an alcoholic.
On the show, Wess revealed that he is gay and said he was met with resistance when he came out to his father. He felt abandoned, with food becoming a source of comfort for him.
Wess also admitted he didn't want to form attachments with people and so tried to make himself undesirable by overeating and gaining weight.
However, the TV personality eventually sought the help of Dr Nowzaradan and was approved for weight loss surgery after tipping the scales at 50.4 stone (705lb).
Wess has so far dropped an incredible 15.7 stone (220lb) as well as going down five jean sizes.
Confirming the news on Instagram, the star said: "OMG I AM FREAKING OUT. I just tried on a pair of jeans… 11 inches or roughly five sizes smaller than I used to wear!
"And they are about one size too big!"
Wess often posts pictures of his weight loss on social media as he aims to inspire those who are on their own journey.
In one recent snap, the reality star smiled for the camera as he posed in his care, wearing a beige knitted hat and green top.
He captioned the post: "Be the you you want to be!"
Fans rushed to congratulate him, with one person commenting: "You look great keep it up."
Another said: "You’re doing such an amazing job, out of all the other episodes I’ve watched, yours connected with me the most. Thank ya for the inspiration!!"
"LOVE THAT FOR YOU My bf and I are cheering you on," a third fan gushed.
Wess also delighted fans when he announced he had recently completed his first one-hour workout session at the gym.
He said: “I’m tired… BUT I DID IT! 220lbs down!”
The TLC star also revealed that he is "single and ready to mingle" and is on the lookout for a partner who can handle his "level of craziness".
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