When and how often you feel hungry is a well-documented to be a conditioned response based on eating patterns, it isn't intrinsic unless you go quite a long time without eating. Human eating patterns have considerable flexibility. A person with a normal metabolism can habitually eat one meal a day without being any more hungry than someone that eats three meals a day with snacking in between.

Unless they are on a particularly aggressive program of calorie reduction, eating less than they are eating now is not asking them to be perpetually hungry.

I was under the impression that you can cheat yourself a bit by eating unlimited food but low-cal. Vegetables are one way (they're mostly water and fiber), but I'm not a picky eater and mostly eat to feel full, not for the taste so YMMV.

They can be perpetually hungry or perpetually unhealthy and obese. Choose you poison.

Getting to explore what it means to be 'hungry', i.e. asking yourself "Is this feeling I need to eat habit or actual real need?" is a large part of controlling/regulating food intake. This 'exploration' used to be engendered by religious practices of fasting and also, times of food scarcity. We don't have either as widespread experiences these days, so the only people who explore their hunger and eating habits are mostly people with a drive to develop awareness around their bodies and who work to identify and then pull themselves out of 'bad habits'.