That's my big problem when people say that fat people need to just eat less. Normal people leap to a reasonable assumption that fat people are getting fat on, you know, food. But live in a fat area long enough and you learn something pretty quick. There really are a shit ton of people out there who are essentially staying alive by eating hundreds of servings of empty calories that deliver around 0.5 or 1% of various nutrients.  Fats in the overweight range usually eat normal food plus lots of empty calories. But the further into outright obese you get the more the ratio flips. You don't turn into a mountain of lard without empty calories. And a shit ton of them at that. Plus empty calories are what keeps them eating in the manner they prefer. Not eating to sate hunger. But shoveling food into their mouth continually just for the sake of the experience itself.