The consensus I've picked up is that if you focus on just eating the right macronutrients and getting some exercise, everything else usually works out - try to replace sugar, refined starch, and processed fruit/vegetable product with protein, lowish glycemic index starch, and less bland fruit/veg.

Another idea that was useful to me is that mass-produced food has to have a low water content, or else it goes bad really quickly, and so replacing water with fat is a great way to make mass-produced food better. But in fresh food there's no such limitation. This means that eating fresher food basically substitutes fat for water in a lot of your food items.