World's fattest man to undergo gastric bypass surgery

Juan Pedro Franco is ready to lose weight. Photo / AP

Tipping the scales at half a tonne, Juan Pedro Franco hasn't left his bed in six years - until now.

Dubbed the world's fattest man, the 32-year-old Mexican was taken to hospital for lifesaving medical treatment yesterday.

Special equipment was used to transfer Juan Pedro, who weighs 500kg, from his mother's house in Aguascalientes to a gastric bypass facility in Guadalajara.

Juan Pedro Franco, who weighs almost 500kg, is receiving treatment at a hospital in Guadalajara, Mexico. Photo / AP

"I never knew what was happening to me," Juan Pedro said.

"My body just followed its own path without any control whatsoever. I tried to diet day after day, but nothing worked and I became desperate. Finally, my body suffered a bad reaction and I was in a coma for a while, waking up in bed from where I haven't moved since."

He added: "This is no life; the worst sentence you can give a human being is to make a prison of his own body."

Juan Pedro's mother said her son was active as a boy, playing sport and dating girls, but his health deteriorated after a road accident at age 17.

Doctors said Juan Pedro has type 2 diabetes, thyroid problems, hypertension and liquid in his lungs.

"His hypothyroidism has done terrible damage to his organism, slowing processes down and causing his body to store rather than burn off what he ingests," Dr Jose Castaneda said.

"He is probably only still alive due to his youth. It's impossible for the human body to cope with the pathologies Juan Pedro suffers from over a prolonged period, but I think we are just in time."

Dr Castaneda said Juan Pedro will need at least six months of treatment before he can undergo gastric bypass surgery.

Mexican Manuel Uribe was once considered the world's heaviest man, before he died in 2014 at age 48. Uribe's peak weight of 560kg was certified in 2006 as a Guinness World Record.