> Almost everyone knows what "healthy food" looks like without needing to know anything about much else.

I highly doubt this. A lot of people think stuff like juice smoothies, granolas or dates are healthy. Or more generally organic or grassfed or "no added sugar" or "high-protein" high-sugar or "unprocessed" stuff.

People are actively misinformed about what's healthy by a constant bombardment of ads, fads and "common sense".