As a psych student, I think Inwoo had conversion disorder, also known as functional neurol...

As a psych student, I think Inwoo had conversion disorder, also known as functional neurological disorder. He developed it due to the psychological stress he experienced while living with his father (I forgot if his marriage also contributed to it), and that stress manifested as a somatic symptom that couldn't be explained medically. In Inwoo's case, he couldn't taste food, but aside from that, nothing else was wrong with him and no other physical issues were present.

Feel free to correct me
I studied for an exam yesterday but the exam didn't happen