Why? What does "not torturing animals" have to do with "eating healthy food", aside from "both are goods"?

One is an ethical position, and the other is self care, which aren't particularly correlated, except that both require self-control.

Which was why it was amusing how much marketing dollars were spent getting it into fast food locations (where it inevitably was a “buy once and never again” for the vast majority of those who even bothered to try it).