Listen, as a girl who has been starving herself on and off from the age of like 11 let me tell you something. Just because Jang Won-young dances and is active does not mean she is healthy or not underweight. I see this logic with lots of idols who are underweight but am using Jang Won-young as a recent example.
Your body is capable of a lot more than you think. Personally, I have had days where I did manual labor for 13h with little to no food (a cookie or two max), and was fine. Days when I looked myself in the mirror and was like "how the hell did I not faint?"
I am 24 and my body is starting to feel the effects of malnourishment but for the most part, I am fine. Jang Won-young is like 18, her body is at its peak (I mean in terms of vitality not physically) so she will be able to do intense schedules.
It does not mean she is healthy nor that she is not underweight. Jang Won-young is underweight, that's just a fact. Now, this is not a discussion on whether we should tell Jang Won-young to eat more or whatever. There is no solution to this. We can send her support, and fight all the people saying they're "concerned" but in reality, are body shaming her but we can't make her eat. Pointing out that she is underweight won't help her either, especially if it comes from a critical perspective.
My mom would do that all the time, pointing out how I had no boobs and no ass, it didn't make me eat it just made me ashamed. Truth is Jang Won-young is part of a society that places extreme value on looks and skinniness. We can't change that, as international kpop fans, our influence on kpop and Korean culture is slim to none.
Ideally, I would ask that we just don't comment on idols' bodies and instead focus on skills and personality but that is not a realistic wish. We can't help Jang Won-young nor can we help all the other idols. However, there is something to be said about not normalizing crazy diets and being underweight. Kpops fanbase is mostly young kids, and they shouldn't think that being unnderweght is healthy or that crazy diets will make them prettier or that they need to have a 10-inch waist.
I don't know what the answer to this is, I don't think there is one. What do you think?