Hi Dr. Ludwig, thanks for reading, I’m a big fan! I agree with your point about the potential for non-linearity of the relationship between sugar and poor health complicating the analysis. Also, assuming the potential for non-linearity, there could also be something like a fallacy of composition: If total sugar consumption is down, but it’s bunched-up in a few groups eating much more, while the people who didn’t eat much to begin with dropped a lot more, then sugar could still be driving poor health outcomes.

To Guyenet’s credit, he came back in a subsequent blog post with some better evidence of decreasing sugar consumption since around the year 2000, namely the NHANES datasets. Although I have minor qualms with the survey instrument because it might not capture changing serving sizes, I think it’s probably reasonable to take NHANES at face-value.

But even granting that sugar consumption has fallen slightly off of already sky-high levels, your points above are a convincing counter-refutation. It really seems like Guyenet’s counter-evidence to Taubes is simply too crude to refute the studies and logic linking refined sugar to adverse health.