In other words, obesity comes from worse diets. The working classes are bombarded with corporate foods that contain way too much sugar, etc.
It afflicts the poor in relatively comfortable and safe nations.
These are diseases of overpopulation, loss of freedom and control over one's life and general lack of anything to live for in the future. Mouse utopia comes to mind.
It's true that obesity is an affliction related to poverty; but it is related to poverty in nations of relative wealth and comfort. Access to that cheap and terrible food relies upon a logistics system that is heavily resistent to famine and blight.
Those in poverty who are dying from obesity related diseases are not dying in work place accidents, and are not dying in war or from untreatible infections. They didn't die in a pandemic.
The opportunity to die of obesity related diseases is tied to the relative safety and comfort of the nations in which the late individuals were impoverished.