One question, every meal

Our whole approach to food could have been forty pages of macros and portion sizes and a colour-coded plate. It is one question instead. Does this food exist in nature.

Meaning, could you have found this a hundred years ago, in roughly this form, without a factory. An egg, yes. A steak, yes. An apple, an oat, a potato, butter, a fish, yes. A cereal bar with eleven ingredients, no. A yoghurt that lasts six weeks, no. A drink that is blue, no.

The reason the question works is that it removes the need to know anything. You do not have to understand seed oils or emulsifiers or what a "natural flavour" is legally allowed to mean. You just have to picture the thing growing, or grazing, or swimming, and if you cannot, put it back.

It fails occasionally, and we admit that. Sourdough exists in nature about as much as a wheel does. But as a rule to live by in a supermarket at six in the evening with two children in the trolley, it beats every diet any of us has tried, and it is the rule every ingredient in our own pouch had to pass.