What about stuff like wheat, which is claimed to be both painkiller and gut irritant? It feels better than the alternative, but appears to be actually doing damage / increasing inflammation.
There's also stuff like mate selection- who I find attractive may not be the best person for the relationship goals I espouse. (For example, liking other men in part based on their projected fertility is problematic both because it won't lead to kids and because it's not making best use of that it won't lead to kids.)
Nobody says that human contact is bad, even though many people like it.
Doctors used to say (about a hundred years ago) that human contact with infants was bad, because of the increased risk of infectious disease. Mothers could not resist touching their babies, and so just felt guilty about doing it- but caretakers in orphanages were perfectly willing to minimize contact. Turns out that not touching infants causes a lot of psychological problems! Oops. (Also, mothers make antibodies for pathogens they pick up by kissing / playing with their babies which then get transmitted to the baby through breast milk, so frequent contact can decrease risk.)
I posted recently that "I tend to assume that things people hate are bad for them. CR may be an exception, but it's plausible that evolution would usually select for warnings that one is hurting oneself."
I think this points at an interesting question. If you know that people like a behavior, or dislike it, or love it, or hate it, does this tell you anything about whether the behavior is useful?
I expect that most people reading this question have a handy list-- one that comes quickly to mind-- of things which are good for people but that they resist. There's a tremendous amount in the culture (and perhaps more from somewhat different angles at LW) about people's reflexive preferences being wrong.
However, there's a lot where people's preferences are assumed to be in line with what's good for them that doesn't get much attention. I believe this is because there's a fascination with the drama of self-denial, but that might be a topic for a different post.
For example, people hate long commutes. I've never heard anyone say that long commutes are good for people.
People generally dislike being low on sleep.
Rather few modern people think that liking sex is a problem in itself. (Note a cultural shift-- anxiety about pleasure has been moved from sex to food.)
Nobody says that human contact is bad, even though many people like it.
And there's no cultural consensus that hating spam is bad, even though hating spam is a spontaneous response.
It's implausible that evolutionarily developed pleasure and pain should be completely out of line with well-being. On the other hand, it's a noisy signal. Should it be taken at all seriously?