To practice the principle, eating when your hungry and stopping before full, takes time. I would say it might take anywhere from a month to 5 months to make changes for life. Old habits are hard to stop. I used to say I was an emotional eater but realized that maybe food was the only thing to get me through a trying time. Now that I eat what ever I want when I am hungry I deal with my emotions up front and deal with the situation. If it's something I can fix, I fix it. If it's something I can't fix, I pray and let time take care of it. Yesterday's problem never seems to be the same after a good nights sleep.