Feb. 12, 2012 -- A Las Vegas man who was the unofficial spokesman for the Heart Attack Grill, a medically themed restaurant that embraces monstrous hamburgers, died Monday after suffering a massive heart attack.

John Alleman, 52, who had come to the restaurant to eat every day, was on life support at the Las Vegas Sunrise Hospital after he had a "massive" coronary at a bus stop last week. He was taken off life support Monday.

Heart Attack Grill owner Jon Basso, who was in Alleman's hospital room when he died, told ABC News that Alleman said both his parents had died in their 50s of heart attacks.

"This was really a nice human being, just the greatest guy you would ever want to know," Basso said.

The Heart Attack Grill, whose tagline is "taste ... worth dying for," plays up its image as a gluttonous burger joint, bound to put customers in a food coma.

Burgers on the Heart Attack Grill's menu have names like "Single Bypass," "Double Bypass," "Triple Bypass," "Quadruple Bypass" and so forth. The "Quadruple Bypass Burger," which packs four meat patties and weighs more than 3 pounds, won the Guinness World Record for "world's most calorific burger," packing a whopping 9,982 calories.

The menu also includes sky high-calories sides, such as "Flatliner Fries," which are deep-fried in pure lard.

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Basso goes by "Doctor Jon," but he is not a real doctor. Waitresses are "nurses" and orders are called "prescriptions." Customers, who have to don a hospital gown when they walk in the door, are called "patients." Those who weigh more than 350 pounds eat for free but only after they get up on a scale in front of the whole restaurant for a pre-meal weigh-in.

"If I set the mark at 300, I would go broke. Everyone in the room is 300," Basso said. "They need to know right now if they are eating this way they are going to end up in the hospital."

Despite its medical theme and jovial ambience, Basso, who used to own a Jenny Craig franchise and fitness center, said he understands that his calorie-packed menu is "very dangerous," but that the Heart Attack Grill serves as his "soap box."

"I absolutely think the food I'm serving is unsafe," Basso said. "The only way what I'm doing would be immoral would be if I were to market it as healthy by throwing a cute little side salad on the menu. ... The Heart Attack Grill is the most moral restaurant on the planet Earth because we are absolutely here to make a statement about obesity, about coronary issues, about death and dying and all those things that are prevalent in the society."

As Basso was getting ready to open the Heart Attack Grill this morning, he said he had a bag of Alleman's belongings with him, which the nurse at Sunrise Hospital had Basso sign for because he said Alleman had no family. Basso said he put the bag behind the bar, for now.

"It's kind of an empty feeling," Basso said. "I walked in there to visit my most loyal fan, and I walked out without my friend and a bag of his belongings."

Basso said Alleman, who worked the graveyard shift as a night watchman for a nearby skyscraper under construction, had been coming in every day for the past year and a half. He would order a "Single Bypass Burger," fries and a drink, usually staying up to six hours. Even though Alleman was never on the restaurant payroll, he came so often that Basso put his "Patient John" caricature on their menus and merchandise.

"He literally was there every day," Basso said. "He was definitely one of the boys and so much one of the boys that half the time it seemed like he was running the place."

Basso said Alleman was not overweight but tall and weighed 180 pounds. But his heart attack was the most recent example of the Heart Attack Grill seemingly living up to its name. In February 2012, a man suffered an apparent heart attack while eating a "Triple Bypass Burger," which is estimated to have 6,000 calories. Two months later, in April, a woman had similar symptoms to the man at the restaurant and was taken to the hospital.

In March 2011, Blair River, the former 575-pound spokesman for the restaurant, died at age 29 of pneumonia. Basso told ABC News at the time that his weight had complicated his condition.

Basso acknowledged the irony in his restaurant's name and that two of Basso's spokesmen had died, and customers had had heart problems after eating there, but he said he had no intention of shutting down the Heart Attack Grill or removing his high-fat, high-calorie meals from the menu.

"I honestly do believe I help more people now than I ever did when I owned the diet center," Basso said. "[Alleman's] death serves as another lesson for people. ... I often say I serve burgers and fries, and I also serve food for thought."

Every day, before Alleman left the restaurant, Basso said Alleman would turn, stand at attention at the doorway and give Basso a military salute. Basso would salute him back from behind the bar.

"The last thing I did for him yesterday was to salute him," he said. "I'm sure he is in a better place, if such a place does exist."

Basso said the Heart Attack Grill would be closed for Alleman's funeral, which will be set later this week.