When I am hungry..?!

When I am hungry..?

Hi,
Do we necessarily need to eat, when we are hungry - cant we just drink(sth which contains sugar - hence a source of energy?
But stomach feels not full when we just drink
Does stomach being full has anything to do with having energy?
I mean is it sort of essential to keep the stomach full with taking some solid food(as opposed to just making sure that we have the necessary sugar by lets say taking sth liquid )

Thanks for answering the basic question with patience!

Your post is not very clear. You have multiple questions, which would require a very long response. But, I'll make it short and sweet.

Your theory of just drinking a substance containing sugar would not provide the numerous micronutrients and macronutrients we need to survive. Your systems would slowly malfunction and shut down.

I'm still confused about the stomach question.