Why does food smell bad in an enclosed space even if it hasn't gone bad?

Take buses frequently in Europe and when someone brings in fish and chips with curry, it has a very strong and unpleasant odour that sometimes is almost slightly less worse than a a fart. This doesn’t seem to be the case for sweet foods (brownies, candies)

I read somewhere it has to do with the fact that a lot of foods can be toxic in high quantities (y spices used in them) and the bad smell is an evolutionary mechanism to deter people from being near/consuming it. Things like nutmeg smell really revolting because too much can cause poisoning. Apparently, people don’t find sweet foods smelling bad (much less) because few of them can cause acute poisoning like spicy or fatty food can.

Is this true?

Moved from GD to IMHO.


I think it’s because of the intensity; a lot of that stuff is great when you’re eating it, but it’s very intense, so if you’re not actually wanting to eat or smell it, it’s kind of rank. And sometimes foods smell pretty similar going in as they do going out (or vice-versa, I guess), so maybe that’s part of it.

Similarly, I’ve always found context to have a big impact on how a smell is perceived. You may really like the smell of bacon but if you enter a gym locker room and it smells strongly of bacon, it’s no longer so appetizing!