Mive Hunger/Unusually Hunger!?

I have been going to the gym and lifting weight for about 5-6 months now and usually the next 2-3 days after a very intense weight lifting session I am very hungry. It seems kind of like a primal hunger. I am hungry every 1-2 hours after eating a meal and its kind of ridiculous. I try and eat as healthy as possible because I dont want to get fat! Why am I so hungry? Its as if I have went days without food.