What does it mean if you wake up hungry?

Answer 1

First let's improve the question:

What could be the reason(s) for habitually waking up hungry even when hunger was satiated by eating before falling asleep.

Now an answer:

It would be easy to say the nervousness or insomnia due to nervous is the cause, and in some instance that would be true. But when it is a habit - when one is not waking and eating merely to avoid or placate some unresolved mental problem - one might ask what leads to such habit formation.

The most obvious would be that "pseudo-hunger" insomnia is a learned/inculcated - behavioral pattern (habit) - first conditioned during infancy, during which, among other times in which feeding is used to control behavior, feeding is used in an attempt to make baby stop crying and go back to sleep - mostly stop crying as quickly as possible. Because this pattern has been extended into later childhood as well as adulthood, we can say that one has been conditioned to be hungry at some phase of the sleep cycle. Conversely, because most everyone will resort to the nipple or feeding expediency, we could say that the sleep-hunger conditioned response persists mostly because the habit was not broken early on; not broken by not withholding (by failing to recognize and then wean baby from) the food "reward."