Regarding this irrationality, my pet theory is that the arena of "food" is an attractor for superstition. Maybe it has something to do with the mysterious proc

Regarding this irrationality, my pet theory is that the arena of "food" is an attractor for superstition. Maybe it has something to do with the mysterious process by which you are built from the stuff you eat. From fad diets, to religious diet restrictions, to diet-based "studies have shown" trends (antioxidants!), to made up allergies. It's no accident that most established religions have dietary rules. (Yes, I know some of these allergies are real. And some of the diets have merit.) Diet attracts all kinds of attention, and only a small part of it is based in reality. It's like a projector screen where other anxieties play out.