Research indicates that some of the reasons behind this kind of overeating come from the brain. According to Dr. Judith Wurtman, people who binge are biochemically different from those who don't. It's like aspirin. If you have a headache and the aspirin doesn't help, you stop taking it. But if it does work, you keep on taking it for headaches.
Food can work that way for some people when they're feeling stress and depression.
Eating certain foods, such as sweets or starches,leads to the production of a calming chemical in the brain called serotonin. When serotonin is produced in large enough amounts, it makes people feel less anxious, less depressed, more alert and emotionally stable. When unavailable in sufficient amounts, it can cause a person to feel depressed and anxious, as well as induce an urge to eat sweet and starchy foods. This process happens in everyone, but some people are more sensitive to its calming effect. This relationship with food starts the cycle.