Food is the cheapest and most easily available coping mechanism for having a shitty life. You don't see that many rich fat people in the US any more, they are the ones going to gyms, fitness clubs and yoga classes.
Most fat people in the US are poor people. They have little or no joys left in life after they pay their bills and have a few hundred bucks left for the entire month, so they splurge on cheap junk food like potato chips, chocolate, frozen pizzas and ice cream to get a small dopamine fix.
Telling these people to 'just stop eating' isn't going to fix the problem when their only other alternative of feeling any happiness after wageslaving 12 hours would be illegal drugs (too expensive) or committing crime to get more money (probably end up in prison and even more depressed).
The problem isn't these millions of poor people eating too much. It's that they cannot simply take vacations abroad, go water skiing in the Caribbean, snowboarding in Switzerland or even afford an imax movie ticket to get happy experiences. Most of them are stuck between their dead-end job and their home couch because they have no money for anything else no matter how frugally they live.
(I am 12% body fat myself, just wanted to provide another point of view)