Nutritional science is largely statistical. Statistical high correlations are often confused with causality. Less often in Physics, primarily because in Physics, design of experiment can do a much better job of isolating variables. Certain nutritional correlations can be tied to causality through links to other experimentally-based sciences. The rationale for banning trans fats is one such nutritional science correlation that can be tied to experimental biochemistry. All natural fats have even numbers of carbon atoms in their side chains, and all unsaturated fats have cis bonds. Our bodies never evolved efficient mechanisms for metabolizing fats, such as the fats with trans bonds and uneven numbers of carbon atoms in side chains, that are found in hydrogenated oils. The implications of ingesting large amounts of such unnatural chemicals are still being determined, but it’s not a pretty picture. My money is on the side of their biologically strange metabolic artifacts being catalytic poisons for otherwise beneficial fat metabolism pathways. Nutritional science may identify some of those implications in its statistical analyses, but it is up to the biochemists to resolve the details. Perhaps they are too busy patenting genes just now.