I think it tends to be the case that rich people high on the social scale tend to be thinner than poorer people. It’s chic to be thin, and they want to be chic.
Possibly being poor rather than being fat may be primarily responsible for those people who are at once both poor and fat dying sooner, if only because they can’t afford the best and promptest medical care.
You mentioned that the poor "can't affford the best and promptest medical care," but that's only relevant if they're sick with something! It might result in a poor man's dying from a heart attack, where a rich man in the same would survive - but he had the heart attack for some reason other than income.
Rich people don't work. They can exercise all day and afford to hire a chef to fix nutritious/delicious meals. They also don't have to try to feed a family of four on $7 either.
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Possibly being poor rather than being fat may be primarily responsible for those people who are at once both poor and fat dying sooner, if only because they cant afford the best and promptest medical care.
IMHO, poor people tend not to have a lot of things, but most people who are both 'poor' and obese tend to live on frozen dinners and McDonald's.
That high-fat, over processed food will kill ya!