"The question I would ask someone who is considering eating there is, 'Why are you doing this?'" Ayoob said of the Heart Attack Grill. "At some point, people are just going to say, 'I don't want to go eat there and now would be a good time to do that, I would say.'"
Although he wouldn't eat there himself, Ayoob said, he understands the entire point of the restaurant is to be "anti-good eating."
"Are they catering to a particular crowd? Yes," he said. "It's almost like saying I'm going to defy all the healthy-food people and the nutrition people.
"The kind of people that are going to go there may not be ready to make a change," he said.
Dr. Jon disagrees.
After years spent operating Jenny Craig centers and personal training studios, Basso said, he has learned that the best diet includes one "cheat day."
"I don't tell anybody to come in here seven days a week because they're going to die," he said.
But he does advocate for a diet that lets patrons take a day off. "If you do that and come to the Heart Attack Grill and blow off steam, you are significantly better off than any other diet on the market," he said.
But Basso knows there are people who would like to see him run out of business.
His restaurant made headlines in 2006 when a letter arrived from the Arizona attorney general, notifying him that the Arizona Board of Nursing had taken exception with the restaurant's waitresses dressing up as and being referred to as "nurses."
Let them yell, Basso said of his detractors.
"I'm still prescribing diet and exercise," he said. "It may be high-calorie diet and lack of exercise."
Basso said he also likes that his restaurant, which seats 100 and is often "packed," offers an environment of acceptance to overweight customers who are typically "demonized" by society.
The scale that weighs customers trying for the free meal is strategically placed at the center of the restaurant where other diners can watch.
"Everybody applauds for them, cheers for them, a big smile comes across their face and for once they are finally accepted," he said. "They're not picked on here."
A typical meal for River at the Heart Attack Grill -- once he weighs in to prove he tips 350 pounds, just like every other customer -- consists of two "single bypass" burgers, a soda made with real sugar cane and unlimited "Flatliner Fries."
He tried his first "Double Bypass Burger" recently but hasn't worked his way up to the "Quadruple Bypass Burger" -- four meat patties with cheese and toppings. And by meat patties, they mean business; each patty consists of a half-pound of meat.
His boss said he has big plans for his new star: an upcoming nude photo shoot done in the style of Burt Reynolds' classic Playgirl pose, only with Heart Attack Grill "nurses" catering to River in the shot.
"I feel fine. I feel good," River said. "I'm happy.
"I don't eat there every day, every meal," he said. "I still go to Subway."