LOS ANGELES • A former contestant of an American reality TV show, who shed more than 180kg of weight, has died at age 29.

Mr Sean Milliken, who starred in My 600-lb Life, died on Feb 17.

Gossip portal TMZ reported that he succumbed to complications from an infection.

"(On) Sunday, he was having problems with his breathing, they were able to resuscitate him and a short time later his heart stopped," his father Matt Milliken said.

People magazine reported that Mr Sean Milliken weighed as much as 408kg and was on the show for only one episode in 2016.

Other media sources noted that he had stated in the episode that he knew he would not make it past his 30th birthday.

He lost more than 180kg over the course of his weight-loss journey, said TLC, a television network that airs My 600-lb Life.

He became bedridden during his senior year of high school , after suffering a debilitating leg injury, People noted.

Mr Milliken said in the 2016 episode that he turned to food at a young age to cope with his tumultuous relationship with his father.

"It was scary. So I would eat. And suddenly I felt a lot better.

"In that moment, nothing else mattered," he added.