The basic idea is that there is a big difference between your assimilation of nutrients when your eating even the smallest amount of cooked food compared to when you eat 100% raw. When you stop eating all cooked foods your assimilation of nutrients increases dramatically to the point where you are assimilating almost everything you eat. When you are still eating some cooked foods your body is still having trouble assimilating everything. This is why people say to eat all raw foods, especially when trying to cure diseases. You want the maximum amount of assimilation you can get from foods, which you can not get by still including some cooked. I hope this makes sense. Victoria Boutenko explains it well in her book 12 Steps To Raw Foods. It also has to do with cooked food addictions. Think of it as being an alcholic. You have to stop drinking all alcohol. You cant keep drinking a little bit otherwise the addiction is still there.