I’ve heard the difference in odor that the Chinese (and Asians in general) are referring to in re Westerners is that of dairy. Westerners consume milk, cheese and butter in fairly large quantities, ingredients that are pretty rare in East Asian cooking.
Big nosed, butter smelling, hairy barbarians-R-US!
After spending 3 weeks in Asia, you fly into the US and everything is bright, clean and fresh smelling.
Its like when you switched from VCRs to DVDs.
America is a country club and its good to be a member!