It touches on it briefly, but refeeding syndrome is a killer and is very hard to treat even in hospital not in a war zone. Even if the war stopped tomorrow and food was abundant, there’s nowhere to treat patients who have been starving - more will die.
I genuinely had to check Wikipedia to remind myself which civil war we call the civil war. It’s the Roundheads apparently, and even that’s split into the civil war I, II and III. Ridiculous.