Based on this Wayback snapshot it seems to be a paper called “A Contamination Theory of the Obesity Epidemic” by Ethan Ludwin-Peery and Sarah Ludwin-Peery. I was able to download the PDF of the paper at this link (the main body of the PDF is 63 pages as claimed in this LW post, and the PDF is dated July 3, 2021, which is just before this LW post was published, so it is likely the version of the paper being discussed here).
Based on this Wayback snapshot it seems to be a paper called “A Contamination Theory of the Obesity Epidemic” by Ethan Ludwin-Peery and Sarah Ludwin-Peery. I was able to download the PDF of the paper at this link (the main body of the PDF is 63 pages as claimed in this LW post, and the PDF is dated July 3, 2021, which is just before this LW post was published, so it is likely the version of the paper being discussed here).