> question: can we chose to chose not to eat?

Indeed we can. Though looking at it plainly, that becomes a far deeper question than you might realize. So it makes sense to consider the various reasons why we might choose to do so, and why our decision may be one we can, if you'll excuse the expression, 'live with'. Are we trying to lose weight? Are we protesting injustice? Are we using medical technology to remain alive without eating? Consciousness is, by it's very nature and regardless of its origin or mechanisms, both fraught and perilous.

>That is, are our decisions pertaining to our actions and behaviors resulting from our “self-determination”, not also arising from stimulation-response automata offering the illusion of consciousness where there is only a secondary system based in stimulation-response, not necessarily more complicated but just secondary and acting on the first?

That is a much better question than your first one, but not necessarily as equivalent to it as your rhetoric suggests.

The answer is illuminating, if you are willing to even try to understand it. The truth is that, yes, our decisions (which follow from, rather than precede, our choices, as proven by Benjamin Libet decades ago) do indeed arise from mechanisms that can be modeled as computational, although to say they are "stimulation-response automata" themselves is assuming a conclusion. The 'secret' to self-determination is that those decisions, while arising in the very same brain that produced the choices, are the result of an independent set of "automota", one which includes the (seemingly) impossibly illogical stimuli and response of 'perception', 'experience', and 'mind'. The divergence (whether merely potential or actual) between the outcomes of these two putatively separate selection mechanisms is exactly what is being discussed here. The choices are selected unconsciously (Freudians suggest the term "subconsciously", but it is problematic) just as any animal executes actions as the result of neurological activity. But the decisions which follow, as explanations for why the action was executed, and provide an opportunity to imagine having chosen differently, are not bound by those choices, and can 'integrate' (if you will) information available only to a conscious creature which is, therefor, thereby, and therefore, able to conceive of things like future and past (independent of the operant conditioning which might determine choices in a simple stimuli-response automata) and desires and intentions and goals and hope and possibility and compassion and morality and 'life as more than simply surviving and replicating genes' unconsciously. In short, thinking and reasoning, rather than computation and logic. The "being" that gives rise to the word for it, not simply the physical existence of it.

As these decisions, teleological examinations of self-awareness, follow our choices, they cannot change them once those choices have occurred, because the decision cannot exist until after the choice it regards has occured, and has unalterably become physically evident. There is no free will, we cannot actually change the direction of time's arrow and reverse chronology to undo the past. But these decisions are not "meaningless", because they are real and they are at least partially independent of the "automata" which produced the choice (and this is both why and how self-determination exists, despite free will, the conventional explanation for it, being impossible) and our self-determinations become part (not a controlling part, but a factual part, and potentially a more powerful stimulus than even biological imperatives or physical truth) of all the future choices, both related by rational connection or simply subsequent in that individual brain. And this, my friend, is what consciousness is.

https://www.reddit.com/r/NewChurchOfHope/comments/wkkgpr/por_101_there_is_no_free_will_only

Thanks for your time. Hope it helps.