The brain's internal state control circuits predict the future by integrating bodily signals and sensory information to estimate meal nutrient content.

“what they're constantly doing is predicting the future they can sense these signals from the body that tell you about what's happened but those signals are slow and and you don't want to wait 20 minutes from the food that you ingested to reach your stomach and then slowly start entering your intestine to figure out what was the nutrient content of the meal you want to try to figure that out as soon as you can right and so the animals learn presumably through just experience that okay something that smells like this and looks like this that has about this many calories and I know I'm this hungry so I'm going to eat about this much and then that information is all transmitted to these circuits to start the process of satiation before the meal begins”