>>507728888Your brain has a protein decay pathway which at the end causes you to be very sleepy.
"Energy" in the scientific sense refers to the ability to move things around, etc...
You can eat all the food with loads of calories in it that you want, yet still fall asleep or be drowsy.
Usually, when people say "energy" they are referring to their ability to be alert and active and direct the energy their bodies contain to achieve intended outcomes.