Although, say as a replacement for dairy milk, I will occasionally have soy milk, I try to avoid processed soy foods like fake meats. Also, you mentioned eating these things in sandwiches which I imagine you make from wheat bread? (Instead of, say, sprouted wheat bread).
I would suggest that you try a week of only Paleolithic foods -- foods that we were consuming before the human advancements in agriculture and the resulting introduction of grains, milk etc. This means lean meats and fishes, fresh (mostly raw) veg and, of course, fresh fruit.