Eating when you're actually hungry is one of the most important factors when it comes to preventing overeating. If you're not hungry but you eat just because it's noon, or because your boyfriend is eating, or because a co-worker brought in cupcakes, than you're not honoring your own body's hunger cues.
Stephanie Clarke, RD, and Willow Jarosh, RD, of C&J Nutrition recommend using the hunger scale to gauge when you should eat and when you should stop. Check in with yourself before, during, and after you eat. Ask yourself, "Am I really hungry?" If the answer is no, stop eating.