I normally don’t comment, but this is completely incorrect. What happened here is that the Korean conscription system separates people into four levels of eligibility depending on health and other factors. IIRC, category 1 and 2 are healthy enough for active duty, 3 is borderline, and 4 is not fit for active duty. This person would have been in a active duty category, but gained weight in order to dodge active duty and either get conscription waived or do alternative service such as public service. This person was not already active duty, but got his conscription notice.

Edit: It’s actually worse. He previously took his medical evaluation and was deemed fit for active duty (either category 1 or 2) and was waiting for an enlistment date (apparently it’s actually hard to get an open spot for military service these days). In that time, he allegedly deliberately gained weight so that when the day came and he had to redo his physical, he would be able to dodge active duty.