NP here. OP, I do a very high intensity bootcamp three days a week and find myself being a bottomless pit on those days too. I am trying to drink a gallon of water a day, which definitely helps on the bootcamp days with me not overeating. I do think a lot of my hunger is actually emotional-based (trying to avoid certain tasks at work, etc) so the water serves multiple physical and mental purposes.

the other thing I do is snack on berries. They're so good for you, they satisfy that need to eat between meals, and they're delicious. I stock up at costco on blueberries, blackberries and strawberries. I should note that in addition to just getting into great shape, I'm actively trying to lose weight, so I needed to address my insatiable appetite.