At that age if they are eating some solids I would have thought they would be OK for that amount of time. Though mine would have probably had a night of "catch up" feeding.
Do they drink anything else? if not I'd be thinking about making sure they had enough water from the food they will eat. Would they be OK with ice? I've know a few people make toddler ice lollies using an ice cube tray and plastic spoons for the sticks.