Interviewed at his home in northern Mexico, where he can still do little more than sit up on a bed, Uribe said more than two years of steady dieting have helped him drop about 550 pounds from his Guinness record weight of 1,235 pounds.
He hopes Guinness representatives will confirm in July that he holds a second title: The world's greatest loser of weight.
But Uribe is still unable to walk his fiancee, Claudia Solis, down the aisle.
"It frustrates me a little, because it is not easy to get out," said Uribe, who has not been able to leave bed for the last six years.
His most recent attempt to escape the house - to attend Solis' 38th birthday party in March - fell through when a flatbed tow truck brought to transport his reinforced bed got caught beneath an underpass.
But Uribe vowed not to be deterred: "We are in love, and this year my birthday wish is to be able to stand when we get married," he said.
Uribe said he met Solis, a 38-year-old hairdresser, four years ago. They have been together for the last two.
"We are a couple," Uribe said. "We have sex, and in the eyes of God we are already married."
Proudly showing off her sparkling engagement ring, Solis said life with a heavyweight is not always easy.
"I bathe him every day, and we get along very well," she said. "At times, yes, people say things ... that it's a fake relationship, but what we have is real."
Solis said her family initially opposed the match with Uribe, because her first husband, who was also obese, died of respiratory failure.
"They were worried about me being involved with another fat man, because they thought another husband would die on me," she said.
Uribe, a former auto parts dealer, said his birthday party Wednesday will be a low-key dinner with the family.
"We were going to go out, but the last time out scared me so much," he said. "When we crashed into the lighting conduits on the underpass, I thought we were going to get an electric shock."
Uribe said his weight problem spiraled out of control after he moved to the United States for a few years in 1988 and indulged in a nonstop diet of junk food and soft drinks.
A botched liposuction that damaged his lymph nodes left him with giant tumors on both legs weighing a total of 220 pounds. The tumors are the main reason he is unable to walk.
"It is all because of the junk food," he said.
About two years ago, a team of doctors stepped in to help Uribe change his eating habits and tackle his extreme obesity.
Today he says he eats small portions of food five times a day, including chicken, ham, egg-white omelets, fruit and vegetables. Sitting in bed, Uribe exercises his arms with pull-ups and by pedaling with his hands.
Hoping his struggle will inspire others, he plans to launch the Manuel Uribe Foundation this year to educate people about nutrition and to combat obesity - a growing problem in Mexico.
Solis is focused more on the present.
"It is a miracle he is still alive," she said. "He's going to turn 43, and that is something we have to celebrate."