Lots of people do emotionally turn to food to help them cope with their depression. When you're in a spiral like that, you don't see things clearly and the cycle continues. Plus it's hard to lose weight when you're already that size, their bodies crave more food. That's why you'll see lots of people fail their diets on shows like My 600 lb life. It's sad for those who want the help, but are stuck in their own depression.