In 1970, obesity in the US was not anywhere as much of a problem. But car culture (and gasoline pollution) was very much a thing. > calorie intake differences

In 1970, obesity in the US was not anywhere as much of a problem. But car culture (and gasoline pollution) was very much a thing. > calorie intake differences Yeah, that's a big one. Also, processing foods heats them multiple times prior to sale, which increases caloric bioavailability.