Cravings can be trained and influenced by person's knowledge, I think. Example: When I was young (and stupid :) I drunk a lot of cola. I literally craved it, I chain-drunk it whole day. Then I learned what that thing actually is, and then my doctor told me my blood sugar is entering regions where it shouldn't be. I didn't touch the stuff since, and now the mere sight of it disgusts me. I tried to drink it, and I realize I actually hate the taste now. I have no idea how I could enjoy it years ago. Maybe I'm just impressionable, but here it goes. I still like the sweets, however, even though with my complexion it is best not to overdo them. I guess it has its limits. But if I gave in fully to my cravings in this area, I'd probably have a very serious health problem by now. So trusting "evolutionary tastes" is a dangerous path - unless you put it under strict control of the higher brain, I believe it can seriously harm you.