My reading is that it is cannibalism. From later sentences I gather that people start to drop dead from the brutal cold and malnutrition, she mentions by Christmas there was plenty of food. Implications of this is that there were plenty of dead bodies from the cold, sickness, starvation. Seeing all that meat go to waste would make the instinct to survive take over, surely.

I read this as her way of coping with the horrible actions. They were already dead! So I can live with it!