How do you know if you are a binge eater?

Binge eating. If on a fairly regular basis you eat much larger quantities of foods than you intend, you could be a "binge eater". People who do this often have preferred foods like potato chips, candy, ice cream, cheetos, etc, that they consume to the point of physical discomfort - and often in secret. Some also purge through vomiting or laxatives; none of this is safe for your health long-term.
Binge Eating. People who compulsively overeat, though, may use food as their only way of coping with negative emotions. As a result, they often feel that their eating is out of control. They think about food all the time and feel guilty, ashamed, or depressed after eating. http://www.webmd.com/mental-health/eating-disorders/binge-eating-disorder/features/compulsive-overeating-and-how-to-stop-it.