It is expected that you save food for other people
Cindy is at a restaurant waiting for her friends to arrive.
Cindy wants to eat food.
Cindy orders food and eats a portion of it, saving the rest for her friends.
Cindy orders food and eats all of it before her friends arrive.
Her friends are delighted to have food ready as soon as they arrive.
Her friends are upset that Cindy didn't save them any food.