New Exercise Routine (with weights) = hungry

Hi, all,

I just recently got back on the wagon with running and lifting. Right now I exercise 3 days in a row, take one day off, exercise 3 days, etc. My routine alternates lifting (full body) and running (or run/walking). I have noticed lately that I am hungry about 2 hours after breakfast. I usually drink a protein shake/smoothie (Arbonne protein powder, fiber supplement, soy/almond/coco milk, and frozen fruits) for breakfast. While I do try to eat 3 meals and 3 snacks a day, I never remember being this hungry between meals. Is this possibly due to my lifting?

Thanks!