A small example of innovation in the supermarket industry. I know that I should eat a variety of nutrients from fruit and veg, but it’s hard to find the time to study foodstuffs in detail. Tesco provide a rough-and-ready guideline on the shelf - at little expense to them, and some benefit to me. I hadn’t come across this before. It sounds like a generalisation that’ll have plenty of exceptions, but is still accurate enough to be useful.