Hungry ape gets woken up early because he needs to go and invest his remaining calories from body fat in to digging up a tuber, or trapping a squirrel or whatever...
Edit. Because obviously the ones with the hunger -> no sleep behavioural repertoire survived to pass on their genes.
I've been on a calorie deficit of 400 for months now and I feel fine. Lost 10 pounds and am pleatueau-ing at 145.
I also work out so my diet is very protein heavy and light on carbs. I don't feel full after meals, but I also don't feel really hungry.
Don't go on an unsustainable calorie deficit. Accept that it'll take time.
I've found that eating less overall can reduce this issue. I assume the stomach and/or mind is adjusting based on food availability.
Having a very good reason not to sucummb to the hunger pains is helpful as well, such as family, sport, etc. I know when I wrestled in high school the feeling of some level of hunger between meals became to be a positive feelings.
It's similar to how having thirst wake you up is a much stronger sign of potential diabetes than "feeling thirsty" during the day.
If it's happening while you're sleeping, it's probably not psychogenic (or psychosomatic).
I haven't found a solution yet.
That way when you increase your intake to something that won't kill you in the medium term, your body is much happier than it would be otherwise.
Works for me. YMMV.
Next thing they make a kind of moral judgment of themselves and decide that to attain for their sins, they need to be punished.
So, they completely change their diets and try to stick to this entirely different diet through sheer will power. It is not going to work.