"Quality nutrition" is any scientifically backed research results on good health.

Here is a resource that uses research to back up its claims: https://www.efsa.europa.eu/en/topics/topic/dietary-reference...

And it has a good tool to find and meet those results: https://multimedia.efsa.europa.eu/drvs/index.htm

The comment I was replying to made a specific claim that I was referring to.

Regarding your definition of quality nutrition, you'll have to be more specific. You can find scientific research to support nearly any dietary choice.

My health has been improving by eating according to this book:

https://a.co/d/2dHgtQr