That does sound very strange that fullness would be delayed.
Overall sounds like the system makes sense otherwise?
Nutrition has little to do with Fullness, and vice versa. They’re really different sensations in any case. I can get lightheaded from lack of energy without really feeling substantially hungry, and I can get hungry without really needing more calories - a common problem in today’s world that leads to easy obesity because we eat so many quickly and easily digested foods with high calorie values, which leave us feeling ‘hungry’ again in a comparatively short amount of time, despite the fact that we just consumed 1000+ calories in a single sitting.
It’s not unlike the fact that your need to breathe isn’t triggered by lack of O2 - it’s triggered by the buildup of CO2 in your lungs. Thus why you can walk into a anoxic environment and not even realize that you cannot breath - you just pass out and suffocate. You were able to exhale all the CO2, but you weren’t taking in any O2 at the same time, so you don’t realize you’re in trouble.
Anyhow, our desire to eat is (mostly) triggered by our digestive system being empty, more than by our actual need for sustenance, though it’s not quite that cut and dried - but the feedback from our stomachs regarding fullness is almost immediate. If you are eating too much, you’ll generally become aware of it as you go, not 10-30 minutes later.
The knock on effects of starvation, dehydration and longer term satiation, of course, can be quite delayed, depending on our current state, what kind of foods we ate and so on.
