What we feel is normally nothing, when we feel hungry (ie not starving, but just need food), we feel a little empty in the stomach, maybe some growling there.

When we feel starving, it is all-focusing the attention on the stomach growling and hurting.

When we have eaten enough, we feel no emptiness, but not overt fullness either. If we have eaten a bit too much, we feel full; but when we eat way too much, we can feel ill.