Today I didn't have to go to class until late afternoon so I tried to eat enough before leaving, but for some reason I felt very hungry/dehydrated during class (and I didn't have any water to drink).  3 1/2 hours later, on the way home from class, I drank almost a liter of water.  Back at home I had nuts and a smoothie- yum! I did not count my calories until after I'd eaten for the day.