Affect serves as a summary of the body's current metabolic state; positive affect indicates a healthy budget, while negative affect suggests a deficit.

“affect is tied to the state of your body or actually what it's tied to is your brain's beliefs about the state of your body your brain is modeling the state of the body and that's interception”

“the way I describe it is that you can think about affect as a quick and dirty summary of the state of your body budget if things are going reasonably well then you'll feel okay you might even feel Pleasant if you're running a deficit in your body budget then you're going to feel fatigued or or distressed”