So many idols have undergone substantial weight loss over the past couple years. YooA, Yena, Yuri, Somi, Ryujin, Chaeryeong, etc. For Izone, the girls all seemed to decide collectively to drop weight during their hiatus after the rigging scandal.
For Wonyoung specifically, she has so many endorsements going on right now that the pressure to look perfect must be unbearable particularly for someone who just turned 18. And that's not even including the pressures of being the center and face of the most popular GG in Korea right now. She has the weight of the world on her shoulders.
even male idol look a lot thinner nowadays,many male idols from the second generation are getting a lot skinnier than they used to since the beginning of the fourth generation.