Nutritionists will never find out that, because it's not their job. They simply recite memorized mantra.
However, some scientists have been creating a mathematical model that should be able to predict the best diet for a particular person, given that the microbes in said person's guts are analysed first.
However, some scientists have been creating a mathematical model that should be able to predict the best diet for a particular person, given that the microbes in said person's guts are analysed first.
You can read about it here: http://www.sciencealert.com/your-gut-bacteria-determines-whi...