I'm right there with you, I don't get it, but if it helps you drop the weight and get healthier - OK.
I was clearly eating more than I needed, but also understanding how many calories were hidden in my diet was a very key point. One ah-ha moment was when I realized that all of that southwest sauce (at Subway) they put on was actually 2-3 servings, and it was costing me 200-300 calories!
Once I started logging my food, it was very clear where the changes needed to be made. Yes, you're hungry for a long time, but your ability to ignore it improves and you don't even notice.