the rhetoric here implies that such illnesses are primarily about conscious choice and will, the conclusion is that humans in america before 1970 were stronger

the rhetoric here implies that such illnesses are primarily about conscious choice and will, the conclusion is that humans in america before 1970 were stronger people No, that conclusion is incorrect. And equally valid hypothesis is that "industries" have become much better at making people choose against their own interest (and against their health). Maybe television has played a big part in that?