A 57-year-old Brisbane man claims he has been unfairly dismissed after he was deemed 'morbidly obese', The Courier Mail reports.

The Northgate factory worker, Lance Pedersen, has been employed by Golden Circle for 14 years but was shocked by his sacking after a medical assessment declared him unfit to do his job.

Originally employed as a forklift driver in the sugar plant, Pedersen was recently told he would be moved to work on the beverage line. His new role would require him to stand, pack and oversee drinks when other employees took breaks.

A medical test followed, eventuating with several noted health risks including morbid obesity and osteoarthritis of the knees. Pedersen was subsequently sacked.

"It pretty well shattered me; it's turned my life upside down. My partner and I have a mortgage ... it's hard to survive on one job." Pedersen was quoted as saying in the Courier Mail.

Filing for unfair dismissal with Fair Work Australia, Pedersen says Golden Circle gave him no warnings about his health and that it had never previously been an issue.

"I've never had anyone complain, I've never had any written warnings. I haven't had people have to help me with the job." he says.

A report from Pedersen's GP states that he is aware of his condition and is capable of doing the job he was originally employed to do.

In response to the unfair dismissal claim, Heinz Australia, the owner of Golden Circle says that they have "an obligation to ensure the health and safety of all our employees," said a spokesman to the Courier Mail.

The company says it had consultations with Pedersen and his union representatives and explored alternative employment options for him. No other jobs were available.

"We are therefore unable to continue to employ Mr Pedersen."

Pedersen, who claims to have since lost 8kg, says that Golden Circle's decision to sack him due to health issues has made him unemployable elsewhere.

"If I went to another place to seek employment I'd have to disclose that Golden Circle put me off on medical grounds. As soon as you say that, the other place will just say: sorry, we don't need you."