Speaking as an American with a formative decade overseas, I think some of that may come from the economics of international trade.
People think about a faraway place based on what gets transported and sold from there. If a country's most-visible exports are gourmet food, you'd start thinking that perhaps the average resident is a gourmand. In the case of the US, those "cultural exports" often involve branded goods, copyrighted media, food franchises, etc.