Natty or not? Natural or not? What does this mean?
Nature
Nature is about growth. Growing muscle, growing bones, sinews— anything which is good for life, and especially human life.
No more “nature deification”
Humans are superior to trees, dogs, animals, cows, pigs, chickens, and every other living creature on earth. Humans are the apex predator of planet earth. We are not a disease on the earth. The earth is our slave. And all the animals and plants on planet earth is also our slave.
What does “nature” mean?
Nascere— to bud, to sprout, to beget. From “genh-”: to beget, birth, produce, etc.
Thus, the notion of nature or natural should probably pertain to active verb matters. For example, let us not talk about what is “natural” or not, but simply what gives birth to things, what produces things, and what grows things.
Biological vs Synthetic
When people talk about “natural”, I think they mean to say biological.
For example to gain muscular gains “naturally” means to NOT take steroids, testosterone, or other things produced externally of your body, perhaps in some lab or something.