I'm not convinced that there's a coherent concept of real food. Most real food advocates I've seen are happy to eat, say, tofu. They'll admit that technically it's processed, in the sense that it's industrially manufactured by pulverizing soybeans beyond recognition then adding chemicals to the big holding vats. But people say it's not highly processed, or it hasn't lost the natural essence of soy, or whatever. I just can't find a way to extract a meaning beyond "the kind of food that real food advocates like".