When I'm tired, hungry, and/or thirsty, I crave a drink. So when I know I'm going to have a busy day, I take Vitamine C in the morning and at noon. I always have something to drink with me, usually club soda because the bubbles fill me up and the water has a little "bite" to it, but diet coke works, as would any fruit juice. I used to keep candy too, but now I've sworn off obvious sweets for a while, so I keep raisin bread wrapped in cellophane and apples handy. For the moment, that has worked for busy,tired, hungry days.