A reasons for over eating are.

1Artifical meal, with substances,salted, sweet,fat, to keep meal before,as search her for low price and buy earlier, big holiday in mayonaise salad, desserts with cakes and pies, as mixing meal will stop to filling stomach,and pancreas will not survive this, as drinking of sweet drinks and alchokol. 
2.Psychologic reasons ,when emotions are poor,we change theirs on meal, meal saves from stress, mobility life and loneliness, and habits for  eating before tv, computer, our minds are far away,and we are non controling for meal eating quantity, eating more.
3.Family traditions,and feeding for childrens.
One spoon for mother,father,as she cooked  for you these pies ,why you do not eat theirs, to hear this he try to do more and more,for snacks and sweets eating,as for good work,or behavior.
4.Big pauses between a meal time,as fast eating as snacks, something, waiting,as because of poor time,we eating after all,my stomach is empty and appetite is big,after work,school you will a feel more fatigue.
5.Non rational shopping,as often visiting actions, for meal for low price,were to remove will not need for you,they are fast  will be a bad.