"Es que ya tiene hambre?"
Why is this question preceded by "Es que" which apparently means "that is" or something closely related. In fact, Why does this phrase need to be in the subject question at all?
3 Answers
Could it be if a baby was crying and someone said:
Do you think it might be that he's hungry already?
ie - Is it that he already is hungry? 
It could also be mean "I take it". Lets say you have prepared a meal for someone who may not be a close friend, hence the informal "tiene" they arrive and you don't want it to get cold. Couldn't you say
I take it you are already hungry (Meaning lets start eating).
But as others have said, more context would be needed.
Es que ya tiene hambre?
I'd guess that there is an element of either surprise, exasperation or resignation in the phrase because of the Es Que....
...and now you're hungry" What! you're hungry now?" or Don't tell me he's hungry now! perhaps about someone who has refused food at the usual times and is now in a car on the motorway where none is available.
Without context it's hard to say but it looks and feels that way to me
