system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If you go to sleep hungry, why do you wake up significantly less hungry than you were before?
gpt
The amount of sugar in your blood stream has a big impact on how hungry you are. When you eat something with sugar your blood sugar immediately rises. As time passes your body uses that sugar for energy and your blood sugar levels get low. This causes you to feel hungry, however if you wait long enough your liver will process stored fat to increase your blood sugar levels. That's why if you ignore your hunger(or sleep through it) you will feel less hungry.

Edit:

Unless you're diabetic. Then you should probably not go to bed hungry.