Chinese consumers may be losing their appetite for American fast food. On June 8, McDonald’s Corp. (MCD) reported that same-store sales fell 1.7 percent in Asia Pacific, the Middle East and Africa in May, the biggest decline since at least 2004. The pullback at the world’s largest restaurant chain coincides with a slowing Chinese economy. That has forced McDonald’s and Yum! Brands Inc. (YUM), which runs the KFC and Pizza Hut chains, to fight back with less-expensive menu items, said Steve West, an analyst at ITG Investment Research in St. Louis....