Dieting is a necessary part of life for many Kpop stars and these four trainees have been making their rounds on community forums for their tremendous weight loss prior to appearing on 'Produce X 101.' 

Check out the crazy before and after photos below!

Nam Do Hyun (MBK)

Nam Do Hyun is known for his height and his baby face. Although he used to be a bit chubby back when he was younger, netizens were quick to point out that he lost a lot of weight and has upgraded his visuals. 

Lee Eun Sang (Brand New Music)

Lee Eun Sang has proven to be a popular trainee and netizens have uncovered a cute picture from his middle school days when he still had baby fat! 

Son Dong Pyo (DSP Media)

Song Dong Pyo has shown that he has lost a tremendous amount of weight in order to be a Kpop star and it seems like the hard work paid off! He's currently popular for his small face and cute visuals. 

Cha Jun Ho (Woollim)

Cha Jun Ho has definitely shown a huge change in appearance since his childhood and his distinct facial features and jawline have been the talk of the town.