It's amazing all day long I am freezing cold but the moment I ate dinner I warmed up some. WTF.

Digesting food is laborious for your system.

Was the food warm?

Because digestion of food, especially ones like meat, require a lot of energy to digest.
This speeds up your metabolism.

When you dont eat much, your metabolism slows down.

There are other factors too like endorphins, stress etcetera.

But we are a bio-electrical organism and the type and amount of intake can affect us physically, mentally and emotionally 😊