I'm like that on days prior to Aunt Flo and also periodically I'll just have hungry days.
Cravings are different. If I'm craving something specific but don't know what it is, I'll start with about 16-32 ounces of water with lemon. Then I can usually tell what I'm craving unless it was just simple thirst, which I mistake for food cravings quite often.
Like the others said, boosting protein consumption throughout the day has made a difference for me, but if I have a particularly blazing workout, I will almost always have a hungry day the next day.