First, someone who chooses to lead such a minimalist lifestyle must also cook and eat correspondingly. Second, the issue of smoke and odor caused by cooking can be resolved easily by an efficient ventilation system. Third, my entire flat is painted white, and all the cabinets are also white. I have been living there for more than 15 years. There is no staining of the walls. The wall color and the cabinet stay pearly white. Unless you are a smoker, there is no reason why your white walls will turn yellow.