There’s no such thing as a concrete standard of morals.

My sociology professor used to say: "if you look far enough in human societies, you will find examples of just about everything imaginable being accepted, or restricted except for incest and cannibalism, those two have clearly observable problems and generally societies will shun them eventually - with notable exceptions such as the Hapsburgs of Europe and the odd cannibal tribe in the Pacific.

It’s an extremely complex question because each of those questions that arise also have a million questions to answer to get the answer to them. And all of them being “right” or “wrong” rely on large scale social acceptance of the answers to each other questions

For an AI to participate in such discussions, it - like a human - would need to learn the locally accepted social mores and synthesize any gaps from the available information. The final result for this and similar questions will depend heavily on the society it is learning from - uncontacted tribes in the Amazon will have different answers from tribes in equatorial West Africa, and of course different answers still from Christian, Muslim, Hindu etc. etc. (each of those having dozens to hundreds of sects...) There is no global answer.

AI doesn’t have sentience. It can’t feel emotion and therefore can’t reason using emotion.

To the extent that emotion is expressed in lexical tokens it can process, AI can process those tokens in context and "feel" to the fidelity that writers can express what emotion is and how it should / should not, does / does not impact decisions.

...losing weight is simple... that can be extremely HARD for most people to actually do.

Knowing the physics doesn't make self-control any easier. Losing weight is a behavioral thing and many of the factors in the behavioral choices aren't under rational control - the decision to eat is strongly driven by all kinds of biological factors that don't care about your reason and philosophies. I wonder what similar problems AI may develop in the future as an emergent behavior of other things we are building into it.