I was this way with my first baby. This time, I've had to use a LOT of self control to not eat that way. I lost 20 pounds initially with my first pregnancy just by eating well in the first half of the pregnancy, and then I gained 55 pounds from 20 weeks on because I was eating non-stop!!!!!!! I can't do that again... lol
I've found that what keeps me fuller for longer is meals packed with healthy fats and protein... For instance, I cook up 3 slices of bacon and scramble 3 eggs (No milk - I don't need the extra calories) in the grease. I'll be full for 3-4 hours with that! When I eat something carb-based, like a sandwich or pasta, I'm hungry again within 30 minutes to an hour. So, I've cut grains and eat fats and proteins (and fruits and veggies) now. I'm not saying go nuts like I am, but try getting in much more protein and less grains just to help control the hunger - it takes a few days for your body to adjust, but then I stopped being hungry!