... until a few years ago, the man grew up, selected his genes without a machine to extract juices!
We each have one incorporated!
Regarding eating habits ("rigidity" in my tastes), I experienced a long time ago, a radical change, albeit temporary (about six months) of my diet, with deletion total of all fat and many other things * ... I ate things not too much for my taste, very little variety and no accompaniment of any kind: (this for the excellent reason that my liver had been reduced to the shadow of himself by the action of a virus a bit dwarf who still had the kindness not to work everything, which would have irreparably damned me ...
I must say that, apart from a little painful beginnings, I have been quite comfortable with this Spartan regime and I deduce that cultural issues mainly shape our likes and dislikes.
* Some of which did not bother me, like alcohol, and for good reason!