My guess is that the “eat every couple of hours” business was started by a sugar-burner who kept getting hungry and didn’t know how to control the cravings. Now that I’m fat-adapted, I’m just not interested in food most of the time, and sometimes when I think I am hungry, it’s just cravings, not real hunger.
The old cliché about filling up on Chinese food and being hungry again an hour or two later was certainly true for me, and the reason was all that rice, combined with the enormous quantity of sugar in the sauce (yes, even in sauces that don’t taste all that sweet!). I was consuming an inordinate amount of glucose, my insulin was spiking, and then my glucose level was dropping precipitously, so I felt hungry again.
When I was a sugar-burner I could literally stuff my stomach so full it was about to burst and still be hungry. These days, I sometimes can’t finish a meal and have to put it in the fridge for later. My belly never comes anywhere near being full anymore, and I can still go for hours without wanting to eat, because my glucose and insulin levels are no longer spiking and crashing.