Paul Mason, the heaviest man in the world, is all set to tell the world about his weight-loss tips in an autobiography.

Mr. Mason weighing 50 stones (317.51 kg) spoke about the book in hospital, which he left on Wednesday .

The reinforced ambulance swayed from side to side as he was moved on to an extra-strength stretcher.

Specially-adapted bungalow

He was then wheeled through 5ft-wide doors into his specially-adapted bungalow in Ipswich, Suffolk, while being filmed for a Channel 4 documentary.

The ex-postie, 48, who weighed 70 stones (444.52 kg) last October, had a gastric bypass to make his stomach smaller and stop him from eating himself to death. Mr. Mason has been bedridden for the last eight years and was consuming 20,000 calories a day, eight times the maximum requirement for adult men.

It is believed Mr. Mason used to gorge three family-size takeaways in a night.

Now, his book The Journey, will reveal how he lost 20 stones (127 kg).

“He’s been telling people in the hospital how he’s writing this book and it will reveal how he’s managed to lose so much weight. He’s been in good spirits,” The Sun quoted a source as saying.

Mr. Mason started penning his memoir as he recovered from the operation at St. Richard’s Hospital in Chichester, West Sussex, where he stayed for three weeks.

Even after his weight loss Mr. Mason is believed to be the world’s heaviest man.