A banana is not a fundamental energy food.

It is not the banana that gives us energy, but something from which banana is made.

We can see bananas, taste them, smell the various kinds, but deep down there, all bananas are made of something else that gives us energy when we eat it.

Some propose Earth wind and fire.

Some propose Tasty Bits.

Some propose ideas that Gods forge into reality.

Cue the invention of the microscope. The game moves one level down: a banana is made of cells.

Before the microscope, people had all sort of theories, after that, well, cells.

But what are banana cells made of?

Repeat this few times and that's where we are. Banana is now made of tiny energetic stuff flowing in time interacting with other stuff. But, that's as far as we can observe/prove/derive.

What is below this level, well why, a very fertile land for research grants, and everybody having a take on what a banana is actually made of.

Source: a banana