THE Heart Attack Grill's slogan is "Taste Worth Dying For", which is exactly what its unofficial spokesman did.

John Alleman, who dined at the infamous Las Vegas restaurant so often that he became its mascot, was waiting for a bus outside the eatery when he collapsed.

The 52-year-old security guard was featured on the Heart Attack Grill clothing range and acted as unpaid spruiker.

The Heart Attack Grill gained worldwide notoriety for its high-calorie menu which included the record-breaking 9,982-calorie, 3-pound Quadruple Bypass Burger.

It employs waitresses dressed as sexy nurses who "prescribe great-tasting, high-calorie meals including the Double Bypass Burger, Flatliner Fries, Full Sugar Coke, Butterfat Shake and no-filter cigarettes!"

Mr Alleman was "prescribed" so many burgers - often teamed with cream-laden milkshakes topped with a dollop of butter - that he was nicknamed "Patient John".

"He never missed a day, even on Christmas," restaurant owner Jon Basso said. "He lived, ate and breathed the Heart Attack Grill."

PICTURES: The notorious Heart Attack Grill

Mr Alleman was not the first Heart Attack Grill customer/mascot to succumb to an early death.

In 2011, another loyal customer, the 260kg Blair River, died of flu-related pneumonia.

Shortly after Mr River's death, a man had a heart attack in the restaurant prompting customers to laugh and take pictures of what they though was a publicity stunt.

And in April last year, a woman in her 40s collapsed eating a double bypass burger, smoking cigarettes and having a margarita.

Mr Basso said Mr Alleman's death was a "wake-up call" but said there were no plans to make the menu less extreme.

"It isn't going to stop us from what we're doing. People have got to live their lives," he said.