It is for his protection. Midnight is actually really late to pull it. Ellie's gets pulled at 9pm before surgery day and water at midnight. Just give him a snack right before. If he were to vomit during surgery he wouldn't be alert to swallow and it can get inhaled into the lungs causing aspiration pneumonia (which can lead to death). Intubation is also supposed to reduce this risk (I think?). No worried, just pull the food.
