Glazed donuts and Philly cheesesteaks? Why not?

Philadelphia restaurateur Tommy Up has struck artery-clogging gold for his PYT burger joint with a cheesesteak served under a grilled glazed donut.

Donut-based burgers are a southern tradition that has been around for a while, as has the cheesesteak -- a Philadelphia delicacy consisting of meat served with melted cheese packed into a long roll. The restaurateur and his chef Kim Malcolm were apparently the first to put the two together. As soon as Up posted a picture of item on PYT's Facebook page, he knew he had a hit on his hands judging from the reaction it generated.

"People were both horrified and delighted by it," said Up, whose full-service restaurant opened in Philadelphia's Northern Liberties neighborhood about 5 years ago, in an interview. "It's been a runaway success."

PYT has sold about 1,200 of the donut-covered cheesesteaks since putting the donut cheesesteak on the menu six days ago, he said, adding the resulting sales "blow my mind."

The Doh Nut has earned PYT plenty of national media exposure, which concerns medical experts who worry about "extreme" menu items like this one as the nation tries to stem the rising tide of obesity. According to data from the Philadelphia Department of Health more than 20,000 residents have died from obesity-related diseases over the past decade.

In an interview with CBS MoneyWatch, Dr. Paul Mather, director, Advanced Heart Failure and Cardiac Transplant Center at the Jefferson Heart Institute Philadelphia, described the "The Doh! Nut" as a "calorie bomb." He advises people who want to try the offering to share it.

"You are going to feel awful afterwards with all that salt and all that fat and all that sugar," he said.

The restaurant is no stranger to what Up describes as "crazy" menu offerings and the Eggo (as in waffle) Monte Cristo Grilled Cheese on the brunch menu is a case in point, as is "The Doh! Nut", a burger on a donut that's topped with chocolate bacon.

In an interview, Up added, "you would be hard pressed to find any (expert) to say that you should never treat yourself." Indeed, he's right. Mather, though, notes that it wouldn't' be a good idea for someone to eat a donut cheesesteak one day, followed by even more meals of fatty, caloric foods.

Up, though, takes the nutrition issue in stride, joking "we are definitely going to keep them in business."

Philadelphia Inquirer restaurant critic Craig LaBan hasn't tried PYT's latest offering yet but told MoneyWatch in an email "it soumds about the right level of mash-up silliness for them."

While applauding PYT's creativity, LaBan added that "the quality of the overall creations rarely meet the level of promotional hype they constantly receive. Not saying it's bad. Just never had one I felt was very memorable or craved a second time."

Up countered that LaBan should try the donut cheesesteak for himself, adding that "you can't review a new book based on the author's previous works."

PYT, though, will ride the donut cheesesteak wave as long as it can. According to Up, plans for a second location are in the works and it has a franchise agreement with Fransmart, which discovered and franchised Five Guys Burgers and Fries.