I don't think you can make the case that nations' BMI is inversely correlated with peer pressure. For one it's difficult to measure, and that tax for example is

I don't think you can make the case that nations' BMI is inversely correlated with peer pressure. For one it's difficult to measure, and that tax for example is a new phenomenon. The US has been an early leader in obesity trends, by way of pioneering mass produced junk foods / fast foods and seeing mass adoption early (and you can make the case for other environmental influences like being a nation that began to be built for driving rather than walking). Other countries who clung on to "old ways" longer had the benefit of seeing the outcome of US approach in this respect and there is little resistance/pushback to both cultural trends and policies meant to deter obesity. All of which to say I don't think Japan's relatively better health outcomes has to do with exceptional peer pressure. Many European countries are more culturally individualist (though less than the US) and still come out better than the US. The other point I would argue is that there are social pressures everywhere, the expectations are merely different. You can also distinguish some by political divide.