Science

In part, according to one of the head researchers, "compared to prior studies that relied solely on epidemiological data, we integrated multiple layers of information, including epidemiological data, conventional metabolic biomarkers, and cutting-edge metabolomics”.

So in addition to finding the meta data, they also dug into the biomarkers present, which already have detailed molecular pathways known. On top of this, metabolomics interpreted the chemical processes involving metabolites, the small molecule substrates, intermediates, and products of cell metabolism. Together, these aspects helped demonstrate the molecular consequences of ingesting animal products. The epidemiological layer assessed the incidence rate of developing T2D and then investigate how many involved the consumption of animal products for the individuals.

This being the case, it appears to be more than just correlation, as once the meta data was found, the team investigated the causation of the meta data's findings.