I am an advanced player, I can claim that by the amount of hours I put in the game, and so far, I have been able to deal with any problem the game challenges me with and I challenge myself with more restrictions each game, but this hunger system is confusing and far from anything I would conclude realistic.
Just because you have consumed a tons of junk food in the morning and have eaten a lot of calories doesn’t mean you can go most of the day not feeling hungry by being peckish and drinking water, people in real life adapt to regular intervals of consuming food, which is a large factor to consider when someone is going to feel hungry. Try eating a bunch of chocolate bars, crackers, smoked meat pieces and not feeling sated and this is exactly what is the result of this system, because in real life I don’t need to drink water to feel sated when I eat that much junk food, it doesn’t make sense. The volume of the stomach is just one factor of many, for a very complicated digestive system that is absorbing a very complex nutritional base this hunger system is somehow trying to mimick to conclude whether you are hungry, slightly hungry of whatever. Somehow in game I drink a lot of water in the morning and go pretty much all day long without feeling thirst doing psychically demanding tasks, very realistic.
I could go on, but meh…