To respect your fullness means to listen for the signs your body sends you when it’s satisfied, approaching fullness and full — and to make decisions about whether to stop eating taking this information into account.
When you eat, start observing your body’s signals that tell you you’ve had enough. If this doesn’t come naturally to you yet it’s to be expected. You may simply need to pause in the middle of a meal and ask yourself if you are still hungry or if you could happily stop eating for the time being.
If you have rejected the diet mentality, have stopped depriving yourself of your favorite foods, are eating when you are hungry and are learning to eat what you want when you want it without apology, you will find that your body will tell you exactly when it’s had enough – if you will listen.