There are many possible causal arrows: * eat fast => no satiety signal => fat * empty carb diet => fat, fast binge eating * high density food => fast, fat *

There are many possible causal arrows: * eat fast => no satiety signal => fat * empty carb diet => fat, fast binge eating * high density food => fast, fat * quality of life focus => (enjoy food => slow, exercise lots => thin) * workaholic => fast, (no exercise => fat) Also, I think you could draw a plausible correlation the other way, along the Norway-New Zealand axis and consider the US, Turkey and France the outliers.