Is this really requiring explanation? You are hungry because you are not eating enough.
^^^^THIS
Not sure what more you want for an explanation. Eat more to get rid of the hunger. I hope you know that eating nothing more than lunch then 5 hours later a protein bar is not going to do much for your workout, on top of that it sounds like you simply are not eating enough. Eat more=less hungry
If by chance I am WAY off from what I just stated and you want supplements to take, well if you train in the morning, take Dexaprine XR. Will take care of the appetite throughout the day. If you train at night, the only thing I used was Lights Out to help me sleep through the night without waking up because of hunger. So cant really say it will take away hunger, but if you wake up from hunger this helped me.