An idiotic term used by many English speaking countries to dehumanize Americans and blame them for all their problems. The object is to portray US citizens as lard machines who are directly or indirectly causing the end of the world.
Person A: Why doesn't this American bank teller speak french!
Person B: Because all those fat Americans can think of is McDonalds.
Person A: Where the fuck are my keys!
Person B: Its all those fat Americans.