Did you take your mask off before eating? You can equip and unequip the mask with Q.
Tapping the number keys to the corresponding food item both switches and eats the food item. One press is essentially chomping on the food, as you continue to chomp on the food the representation of the food on the character should change to show that it’s being eaten. It takes a several presses for the popcorn but if you keep chomping on the food the item will disappear along with a bell sound to signify you finished it.
Thanks for playing, let me know if this worked for you.