"What does cyanide have to do with eating to survive?" It doesn't - exactly like eating meat. You don't need either to survive, and both are completely "natural".

By saying that "partaking in natural things should be free from judgement", you're also arguing that we shouldn't judge someone when they commit murder, rape, incest, and a whole slew of morally objectionable things because those things happen to also exist in nature.

If you meant that, you're too far gone to have a reasonable conversation. If that's not what you meant, then you need to rephrase your argument because "natural" does not mean "good".