Processing food isn’t new: we’ve been doing it for thousands of years (think cheesemaking, fermenting, smoking and pickling). But the surge in foods that are classed as ‘ultra-processed’ really accelerated after the Second World War, when innovations like industrial preservation and formulation meant it was possible to produce convenient, long-shelf-life products at scale. At the same time, home lives were changing, with more dual income households and less time for cooking from scratch, meaning there was greater demand for quick, easy meal options.