why overeating?

Most people are aware that the U.S. has a weight problem. There is much discussion of why, and of course, the obligatory casting of blame on the overweight individuals. True, many people eat too much and exercise too little. Bu why now. Is it really due to some moral decline that we are more overweight than previous generations. I don't think so. And I don't say this out of self-interest, because I have kept my weight down pretty well. I am within the suggested guidelines for my height.
A society-wide change suggests changes in social conditions. have changed. And of course, some are obvious - sedentary jobs, cheap food is fattening, even a possibility that a virus causes some cases of obesity, lack of sufficient food before birth and in the early years causing the body to be more efficient at storing fat.

True, many people eat very large amounts of food. I assume they are eating because they are hungry. But why are they so hungry?

Some possibilities I haven't seen discussed:
I know from personal experience that stress can increase the appetite.
I also know from experience, and studies I have read, that lack of micronutrients (vitamins & minerals) can cause a craving for certain foods. I expect that part of the obesity epidemic is due to a deficiency of micronutrients in our food, causing a craving for enough food to provide the necessary nutrients.