My first post ever included the word 'raw'. The idea was that if you can eat a food raw, then that is good general rule about whether you should eat it or not. This was not to say you MUST eat it raw - it was simply short-hand for which foods to aim for.
We can add to this a further short-hand. Avoid foods that you can't eat naked. By this I don't mean food you can eat in a state of undress, but the food itself; food you cannot eat without a host of added ingredients - principally salt, fat and sugar (other than what might be present in the food in an uncooked/unprocessed state). A good illustration of this approach can be found in this interview with Michael Moss,
- “They made for me special versions of some of their most iconic products … without any salt in it to show me why they were having trouble cutting back. And, I have to say, it was a god-awful experience. … starting with Cheez-Its, which normally I could eat all day long. The Cheez-Its without salt stuck to the roof of my mouth and I could barely swallow. Then we moved onto frozen waffles, which tasted like straw. The real moment came in tasting a cereal — I think it was Corn Flakes — which tasted hugely, awfully metallic. It was almost like a filling had come out of my mouth and it was sloshing around.”