The initial chemo makes them sick and weak. With ALL, sometimes they are given steroids, which keep them up all night despite sedative and give most the appetite of Goliath.
You give such a paed patient ANYTHING they want to eat, at any time.
I can remember when DD1 came home, stocking the freezer and cupboards with whatever she craved. She was tall, but only 23kgs at discharge, so sent home with feed, as she had in hospital.
She wanted Magnum ice cream bars and Chicago Town pepperoni pizzas, Galloway cheddar cheese, ham, rolls and real butter and spag Bol.
You get up and get a child that skinny despite feed putting thousands of calories in her anything she wants, whatever the cost.
She went back in at a few grams short of 28kgs in just 2.5 weeks and her cons was pleased as punch.