We either eat from actual physical hunger, or we eat from emotional hunger. Emotional hunger is when you eat or feel the urge to eat for any reason/emotion other than physical hunger: stress, boredom, anger, happiness, sadness, guilt, depressed, anxious, frustrated, lonely, busy, insecure, rewarding, tired... it can be any emotion.
You've probably used food as a coping mechanism. When you feel an emotion too overwhelming, you try to deal with it by eating. You eat to make the feeling go away but now you feel bad because you're too full. You've shifted the blame from the overwhelming feeling to the food. You can now blame the food you just overate as your problem. But the real problem, the overwhelming feeling, is still there buried under the food. You judge yourself for overeating and you feel guilt, shame, and disgust...more overwhelming emotions that it seems can only be dealt with by eating. Now you have the original overwhelming feeling, the overeating, the guilt and shame, and more overeating.
You can begin breaking this cycle by not judging yourself when you do emotionally overeat. Yes it will happen, again and again and again... It's part of the learning process. When it does happen, instead of punishing and berating yourself, acknowledge it. Think "Okay, I just overate because I feel ________. It's okay, I'm okay...I must have needed that just then". The next time you're feeling ________ and you have the urge to eat, remember this overeating experience. How will eating now compare to when you ate then? Will you feel any different or will it be the exact same thing? Try not eating this time. Find something else to do in place of eating. The food will be there when you get hungry, see if you can handle the overwhelming feeling some other way. Read a book, go for a walk, take a hot bath...get out the list and try something other than eating.
You perceive food as your friend. It never complains, never talks back or stabs you in the back. It gives you comfort, security and even numbs you for awhile. But if you take a step back and really think about it, food is none of these things. The food doesn't care if you're having a bad day or not. All the extra food will do for you is make you feel bad about yourself because you're too full and it will cover your body in layers of fat.
It's time to put food in its place. Our bodies need food for physical hunger, 0-5 period. Any more than that is emotional overeating.