I never let myself go hungry, whilst gaming - if I'm over at a friend's house, they might let me start dying of thirst, with the promised cups of tea failing to materialise over the course of the evening, due to something funny someone has just said and derailing her train of thought from its slow progress across the rickety bridge of coherence. We are not in danger of starving to death, because a pot of food appears before we start and if only the players themselves would tear themselves from LOTRO for long enough to get their kids to bed, we could have a decent session.
But that's tabletop RPGs. When gaming on the computer, with the aforementioned LOTRO, I find that I rest for bathroom breaks, chances to give my stiff neck a move and for sustenance. I break for meals and that is very welcome, but if I head into town, I can set the character to converting the raw materials to trade goods, while I'm grabbing a brew and maybe a pack of biscuits.