Knowledge and our understanding of nature advances, it doesn’t mean there was some grand conspiracy.

Except, you know, it was a grand conspiracy. It was not "our understanding" or "knowledge." It was blatantly the sugar lobby making up "science" and presenting it as fact in order to justify government aided and subsidized expansion. This actually happened. This is an uncontroversial fact.

https://www.cpreview.org/articles/2024/6/sugarcoating-the-truth-the-role-of-lobbying-in-americas-obesity-epidemic

https://www.npr.org/sections/thetwo-way/2016/09/13/493739074/50-years-ago-sugar-industry-quietly-paid-scientists-to-point-blame-at-fat

https://avicennamedicalreview.com/the-sugar-industry-scandal-how-harvard-scientists-were-paid-to-downplay-the-harmful-effects-of-sugar-and-what-it-reveals-about-science-manipulation/

https://home.sandiego.edu/~jkua/access396/SugarIndustry_NYT.pdf

https://longevity.stanford.edu/how-the-sugar-industry-shifted-blame-to-fat/