[hn_throwaway_99]

> And if sugar is so metabolically harmful, where are the RCTs showing this?

Look at the details of this study. The reason there are no RCTs is, at least for what this study looked at regarding very early childhood, they are impossible because they would be highly unethical. You can't take two groups of babies and randomly assign them to control group vs high-sugar group and test for the outcomes.

What this study is arguing is that the lifting of sugar rationing acted as a "best possible" form of a natural RCT as babies born relative to that lifting date had vastly different levels of sugar consumption in the first 1000 days. Note you see these types of "natural cohort" studies in a bunch of areas. E.g. it's not ethical to say group a is the "high levels of lead" group and group b is the control, but by looking at neighboring states that restricted leaded gasoline at different times you can try to tease out cause and effect.

I see tons of comments here arguing "how can they say it's just sugar!" I had a similar initial reaction, but I see very few comments that are arguing about the specifics of the study itself, and I'd argue the study is quite interesting and, at least from my layman's perspective, well done.