For the same reasons as ShotgunSteve and Chaotic42, I absolutely cannot throw away food. I eat stuff dropped on the floor. I eat stuff that is starting to turn bad. I eat my kids' leftovers. If I go to an all you can eat buffet, I make it my goal in life to bankrupt the restuarant.
One of my most vivid memories from 1st grade (1978): My single parent mother and me and my sister came back from the grocery store. My mother had purchased a beautiful, sparking golden gallon jug of apple cider. A rare treat for our broken family. When my sister opened the back door of the car, the jug had been leaning on it. It fell to the sidewalk and shattered. I stood in the front yard and had the awful realization that we *could* not get another.
I felt guilty and frustrated just for seeing it happen. I still cannot write or talk about it without an emotional response. It's funny that something that should be a faded memory is so clear to me 25 years later.
I can't say that I *know* that's why I overeat. Almost everyone in my family is overweight (maybe not so significant, since this is America). But I do think that my "poor" background makes me frugal in the areas where I'm frugal (vehicles, electricity, food, haircuts, household items) and maybe contributed to overspending in the areas that were completely out of reach when I was little (eating out too often, for example).