La Shy: I try to think of wholefoods (as close to the original plant or animal as possible) as basic foods, and processed stuff (has an ingredients list) as processed foods or occasional add-ins. I find flavourings/ condiments the most challenging, but easy to minimise wheat-rich foods (cereals, bread, pasta, crackers, baked goods) with a little practice.
Essential to avoid anything advised by a doctor or dietician, or identified by you as problematic in phase one.
If you focus on adding in wholefoods and eating a really wide variety (Dr Mosley says 20-30 varieties mostly veg and little fruit a week) there is minimal room for processed stuff.
Portions check out your country’s official healthy eating guidelines. UK is 80g fruit and veg, 30g hard cheese, 150g yoghurt, dried fruit 30g, meat size and thickness of your palm. Can fit fermented stuff and seaweed into this, personalising over time. It’s fine to have half servings if something is strong flavoured or gives you gas!