Food concerns all. Everybody has an understanding of it. Some people know more about food than others. People cherish different assumptions on food. Absolute certainty does not exist, but assumptions, right or wrong, provide a vision of what we can expect. Assumptions grow from a mixture of tradition, delusion, knowledge, media perception, fear of death, recklessness, mood, hearsay, earlier research outcomes, experience, intuition, strategic brand influence, habits and probably more. A gluten allergy is far less common than diabetes. Nevertheless, consumers are less inclined to avoid sugar than gluten. Indeed, the market offers gluten-free paint, shampoo, which is pointless, and ditto meat, which is trivial. Markets thrive on lay assumptions. Scientists are not always aware that their own assumptions underpin the knowledge they publish. The other thing is that they often don’t realize that their assumptions on public knowledge define the way in which they inform the outside world. Edibility of spinach, or shrimp is not self-evident.