Why do we have to go to bed hungry?

When you don't eat supper at night, your pancreas starts to secrete insulin.
Insulin can be powerful, like a master key that can pry out the glycogen stored in the liver, providing energy to the body. When the glycogen in the body is almost depleted, your blood sugar keeps dropping.
At this point, the brain receives a signal and starts to shout 'hungry,' reminding you that it's time to eat.
If you don't eat, endure it, bear with it, then your body will quietly activate your fat burning switch.
Once this switch is turned on, the body will start to clean up those extra fats.
For example, the fat in your belly, the fat in your internal organs, the fat in your liver, this behavior is very beneficial to our body.