The last time 23-stone Michael Wynne went on a diet he was six.
His school fed him boiled fish and it put him off trying to lose weight.
Now 42, Mr Wynne is determined to become a slimmer, healthier individual.
He has joined Weight Watchers and ditched a diet of chips and takeaways.
He has set his heart on losing enough weight to take part in a tough three-day cycle ride for charity from London to Amsterdam.
Mr Wynne, a porter at the Sussex Nuffield Hospital in Brighton, said: "I have always been big. I weighed a stone by the time I was six months old. But gradually over the years my weight crept up. It was in my teens, when I liked a pint or two, that I really piled on the pounds."
His downfalls were chips, chocolate and takeaways, which were an easy option after working long, irregular hours.
Michael said: "It is only now I'm working in a hospital that I realise how being overweight affects your health. If I were to need an operation, I may not be able to survive the anaesthetic. I get tired quite easily."
Mr Wynne, of Compton Avenue, Brighton, said: "You always hear about women trying to lose weight but not so much about men who are overweight. We still have the same problems, such as finding clothes that fit.
"I remember mentioning to someone at work I was worried about joining Weight Watchers as it would be all women.
"I was a bit nervous and self-conscious at first, but when I got there I met other men like me. Everyone was really supportive.
"The cycle race will be tough but it gives me a focus. I used to cycle when I was younger but I don't even have a bike now. I have had to start getting fit on an exercise bike.
"I've already lost 11lb and feel healthier. I can't wait to be able to buy clothes in regular shops."
Mr Wynne has been offered the loan of a bike from Action Bikes in London Road, Brighton, to take part in the Mencap charity ride in May next year.
He has already raised £325 in sponsorship money but needs to beat a target of £800.
Anyone who would like to sponsor him should call 07811 508903.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article