because we now have a foundation we can go to in case we're wondering if something is "healthy"*.

Well, kinda. Health is a function of many arguments, nutrition being one of them. The problem is that the arguments to the health function are not independent -- you don't get the luxury of changing just food and knowing that nothing else changed.

To give an example, I know some people who would consider being restricted to Soylent and nothing else to be cruel and unusual punishment, to the degree that the resulting unhappiness and stress will impact their health.

implies we're going back to the ideologies I was trying to kick out.

We're going back not to ideologies, but to values. You can't kick out values and be left with anything useful.