These days everyone knows that fast food isn't exactly the healthiest option. People who fill their diet with takeout burgers, fries and soft drinks have a much higher risk of becoming overweight and developing diabetes or a heart condition.

Scientists at the University of Nottingham wanted to get a closer look at what happens when a fast food burger is digested, so they took a typical McDonald's cheesburger and soaked it in hydrochloric acid for three and a half hours.

They filmed the experiment and posted it on Youtube and so far it has been viewed over 16 million times! If you're a fast food fan, you might not want to watch this:

Hydrochloric acid is found in the human stomach and contributes greatly to the digestion of everything we eat. With a pH level of between 1 and 1.5 (which is very acidic), hydrochloric acid is strong enough to break down food and kill most bacteria before it can do us any harm. If it wasn't for the protective mucus lining, our stomachs would actually digest themselves!

The scientists were quite surprised to see that, even after three and a half hours, the cheeseburger wasn't completely dissolved. Instead they found a very disgusting clump of black goop.

It normally takes 24 to 72 hours to digest food, but the length of time depends on the type of nourishment. Fruit salad, for example, can be digested in as little as 30 minutes, while a Big Mac can take as much as three days to be completely broken down. This has a lot to do with the fact that burgers are full of unsaturated fats commonly known as "trans fats." On the other hand, fruits and vegetables are much easier for the body to digest.

Enjoying a fast food burger once in a while is really no big deal and nothing to be concerned about. But the majority of your diet should be made up of healthy, fresh foods such as lean meat, dairy products, whole wheat breads, fruits and vegetables. The fact is, eating properly can help prevent many illnesses and unnecessary weight gain. A healthy diet my not be as convenient as a trip to the drive-thru, but in the end your body will thank you for it.