Some body art enthusiasts in Japan really like bagels.  Bagel Head is the latest body art beauty trend in Japan, but the process is pretty sickening as it requires having saline injected into the forehead for two hours.

National Geographic's show "Taboo" shed some light on a new fad in Japan called Bagel Head. The process requires injecting saline into the forehead, then pressing a thumb into the swollen area to create a bagel shape. The trend is a new extreme way of modifying the body and it is growing popular among piercing and tattoo fans.

National Geographic shows three people in Tokyo go through the process. John, Marina and Scorpion have needles inserted into their foreheads. They then sit for two hours while 400 cc of saline drips into their skin which causes their foreheads to swell up. The practitioner then uses their thumb to press down into the swollen bulge and create the bagel shape. 

Unlike permanent tattoos and piercings, the bagel head modification only lasts 16 to 24 hours. The saline is absorbed into the body and the forehead returns to normal.

"Right now it's kind of a relaxing sensation, kind of tingly, and also a kind of building pressure that's kind of slow and steady that kind of feels like it's putting me to sleep,"John says as the saline is injected into his head during the process.

While the show, which will air  on National Geographic on Thurs., Sept. 27, is just exposing this trend to the world, the bagel head process has been around for 20 years.

 Artist Ryoichi "Keroppy" Maeda came across the trend in Toronto, Canada when he attended the extreme body modification convention Modcon in 1999. He got permission to bring it to Japan and sparked the trend that is taking place in the country. In 2007, Keroppy set up a team to do the process in the country.

So why exactly would anyone do this?

Keroppy tried to explain the reasoning behind it to Vice Magazine in 2009.

"People who like extreme body modification want to find their own way of doing things, and they're always looking for new ways to do that. The more progressive the scene gets, the more these people have to experiment and go their own way," he said.

Keroppy explained that people have "saline parties" about twice a year in which a group goes through the process, but people sometimes to do it before they go out to a club.

While most people get the saline injections in their forehead, it can be done on any part of the body. Keroppy even said that some had "scrotal infusions."