MONTERREY, Mexico (Reuters Life!) - Mexico’s Manuel Uribe, once the world’s most obese man, is now vying for a different record: the human who has lost the most weight.

Manuel Uribe chats with a reporter during an interview at his home in the suburb of San Nicolas de los Garza, in Monterrey May 9, 2008. REUTERS/Tomas Bravo

Uribe, who weighed as much as a small truck at more than half a tonne, is dieting while confined to a reinforced bed that he has not left for the past six years because he is so heavy.

He has lost 518 pounds since March 2006 on a diet of grapefruits, egg-white only omelets, fish, chicken, vegetables and peanuts.

Now weighing 717 pounds -- the size of three hefty men -- Uribe is still unable to move his swollen legs but hopes to get out of the house next month for only the third time in six years to celebrate his 43rd birthday.

He will still be in bed, hauled onto a tow truck for a trip to the mountainous countryside outside his home city of Monterrey in northern Mexico. It will be a rerun of a failed attempt in March that was thwarted when his bed hit an overpass.

“It’s a miracle I’ve got this far. I was going to kill myself two years ago when my wife left me, but God sent me excellent doctors,” said Uribe, his torso still huge with flaps of puffy white skin and sagging, fatty bulges.

Uribe spent the 1990s eating pizzas and burgers in the United States where he worked as a computer repairman. Addicted to junk food, he eventually tipped the scales at 1,235 pounds back in Mexico, bingeing on greasy tacos.

His bulk made him the world’s heaviest man and won him a place in the 2008 edition of the Guinness World Records. Photos of his time in Florida and Texas show the transformation of a once chubby man to a bloated, whale-like figure.

“At the Big n’ Tall store in Dallas, they no longer had my size. Then I got tailor-made pants and I grew out of those too,” said Uribe from his bed by the open door at street level, where he likes to chat with his neighbors to stop the boredom.

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TEARFUL TV APPEAL

In Mexico, Uribe underwent a tummy tuck operation but it caused massive, permanent swelling, and did not reduce his weight.

Abandoned by his wife, his health failing and with no income, Uribe pleaded for help on Mexican television, stirring up intense international interest.

Uribe, cared for by his mother Otilia, turned down offers of gastric bypass surgery in Italy. Instead he took free medical help from U.S. doctor Barry Sears. He lost weight following the Zone Diet, which is high in protein and low in carbohydrates.

“I was impotent before, but now everything’s working again. Ask my girlfriend,” he said happily, his Guinness World Records certificate hanging on the wall.

Uribe, who relies on his family’s small wholesale clothes business and the generosity of friends to survive, said people at Guinness have spoken to him about his rapid weight loss and could eventually put him in the record books.

Rosalie Bradford, an American woman who died in 2006, recorded the greatest weight loss for a female after she shed 907 pounds. The record for a man is held by Jon Brower Minnoch who lost 924 pounds, according to Guinness World Records.

Uribe, who became an Evangelical Christian during his weight loss drive, said his goal is to weigh 285 pounds by 2010, meaning he would have lost 950 pounds.

Records aside, Uribe just wants to get out of bed and make a living from preaching the benefits of healthy eating.

“I get lots of e-mails from people saying they are inspired by my progress and I want to get the word out about healthy eating. I’m not against people who sell junk food, but you’ve got to be informed not to eat it,” he said.