That's almost exactly what people said about the appetite -- about the biochemical pathways which govern hunger, which are known to be massively redundant and overlapping.

But then Ozempic was released and it turned out there was a shortcut after all.

Which is not to say that such things are necessarily "healthy" or desirable, just that you can't rule out that biochemically-modifiable characteristics, however complex, have "one simple trick!" you can use to attain a desired end.