I use the word 'instruct' because it means to inform, explain and demonstrate. So, I inform my wife and I explain and give examples (demonstrate) as to why I don't want her eating Western food. I will point out fat white women or even Chinese women who have destroyed their bodies, obvious to me, as a result of eating Western diets.
Western men like Chinese women because their bodies and their overall appearences are slim, tiny and delicate as compared to Western women. How many times have you seen overweight white women, black women or spanish women in their 30s that are well past their prime because they haven't taken care of themselves. They smoke, drink and eat fatty foods and they look terrible as a result. I won't accept an ugly wife, so I let my wife know that she has to keep up a certain standard of beauty. I told her that if she gets fat and ugly, I will either tell her to leave or I will fuck more women on the side than I already do. And I tell my wife that since her menu is so terrible to begin with, she doesn't have room to lose her beauty. I can accept a beautiful wife with a limited menu, but I can't accept an ugly, fat wife with a limited menu. My past girlfriends are beautiful and slim and so I tell my wife that she has to be nearly as beautiful as the girlfriends in my life.
Why would I associate with any woman if she were not beautiful? Women bring beauty into a relationship and they also bring the bearing of children. But beyond that, they typically have no value. So, of course I would tell me wife that she better stay beautiful. That makes perfect sense.