I have a theory about this.

I think that this mindset, where eating is a background activity we engage in to sustain life, is the state we are MEANT to be in. I think that before this, when we were eating not because our body needed energy but because an irresistible impulse to prevent our blood glucose from dipping too low and KILLING us had kicked in, a survival mechanism we had no power to control had taken over, I think we're not meant to live like that. Kind of like breathing. We don't think about breathing, but if we try to hold our breath forever, we can't. We can't kill ourselves simply by holding our breath, and even if we succeed in holding it long enough until we lose consciousness (a truly difficult feat to accomplish), our body begins to breathe on it's own, and we eventually wake up. A survival mechanism kicks in. A person who is on the carbohydrate/blood sugar/insulin rollercoaster thinks about food a great deal. A person who is drowning thinks about being able to breathe a great deal. We don't think about having water to drink too much, unless we have been deprived of it for a long time. Even those on calorie restricted diets, they have a preoccupation with food. I read somewhere about the Minnesota Starvation Experiment, about how, even though it didn't go on for a very long time, several of the participants had become so preoccupied with food over the course of the experiment that they actually became chefs.