Regarding prohibitions against pig: More cultures don’t have a prohibition against pig than do, and there are foods that are potentially more unhealthy than pig eaten by cultures around the world. There have been several anthropological models that could explain these prohibitions from a functional perspective (i.e., health, control of protein in the food supply by elites, etc.) as well as symbolically (having the wrong number of legs is icky). I don’t think any of these explanations have avoided intensive criticism.

More important, perhaps, is the apparent fact that there are many, many food prohibitions that make no sense at all. It may be that most food prohibitions don’t make sense, though perhaps a few had origins that kinda made sense at the time.