It’s as simple as eating less calories than you need

Agreed. It’s simple. But simple is not necessarily easy. There’s a difference.

but they can’t manage it because they’ve trained their bodies to expect them to be constantly cramming garbage down their gullet

Sounds a hell of a lot like an addiction to me.

[…] lazy and or stupid and don’t want to make the effort […] cramming garbage down their gullet […] they have no willpower

Your entire response is filled with vitriol. You attribute a serious problem that has become a pandemic to an individual personal fault rather than acknowledge there might be a systemic problem, which leads me to believe that not only do you hate or despise overweight people, but you put them down to make yourself feel superior.