(<a href=story.news.yahoo.com target=_blank>yahoo) Food is running so low aboard the international space station that the two crewmen have been instructed to cut back on calories, at least until a Russian supply ship arrives in a little over two weeks, NASA said. (...) The food supply has never gotten this low before, and no mandatory dieting has ever been in effect before in the four years that the station has been permanently occupied. American astronaut Leroy Chiao and Russian cosmonaut Salizhan Sharipov are barely two months into their six-month stay aboard the space station.