Joanna, I'm in my 36th week too. Starting from the second trimester, I often get so hungry, I'll be woken up in the middle of the night by hunger so severe, it hurts my stomach. So I'll get up and eat a sandwich, or drink a glass of milk.
I figure the baby is trying to tell me he needs extra nutrients! I have not't put on that much weight, so I dont think eating this much is hurting me, hehe.