The meal sitting on the counter at Vaughn Chiropractic consists of a McDonald's cheeseburger, fries and a Taco Bell soft shell chicken taco.

Two years ago Dr. Jaqueline Vaughn bought the meal and put it on the reception desk without a cover.

She notes there are no bugs, "there is no smelling, no decay, the only issue that we've had is people are so intrigued by it they'll pick it up and because the bun now is so … almost mummified."

Fast food meals are notorious for the amount of preservatives they contain … but just how long can they survive and exactly what is keeping that food so 'fresh' looking?

It's a preservative called calcium probinate says Wayne State University Assistant professor of food science Yafan Zhang.

"These ingredients, they have potential to cause some inflammation in our stomachs … unless you eat a lot of this type of food everyday – then you will be okay."

Dr. Randa Marshall says patients reactions have been priceless:

"People will make jokes all the time – 'hey, let's drop some water on it and nuke it – see what happens.'"

The meat, cheese, even the lettuce and pickle are still intact, although they are pale and hard reports WWJ's Marie Osborne.

The display is now more for education and the clinic hopes that people think about what they are eating. Marshall says there is nothing better than a visual.

"A lot of times it's for the kids, we have a lot of kid patients that come in here, they love McDonalds," said Marshall.