PORT-AU-PRINCE, Haiti  Maxi Extralien, a twig-thin 10-year-old in a SpongeBob pajama top, ate only a single bean from the heavy plate of food he received recently from a Haitian civic group. He had to make it last.

“My mother has 12 kids but a lot of them died,” he said, covering his meal so he could carry it to his family. “There are six of us now and my mom.”

For Maxi and countless others here in Haiti’s pulverized capital, new rules of hunger etiquette are emerging. Stealing food, it is widely known, might get you killed. Children are most likely to return with something to eat, but no matter what is found, or how hungry the forager, everything must be shared.

The communal rationing, along with signs all over the city that say “S O S” and “we need food,” suggests that the food crisis here is growing. In a country where malnutrition was common even before the earthquake, the United Nations now estimates that two million Haitians need immediate food assistance. And despite frantic efforts by aid groups, distribution has been limited. As of Saturday, the World Food Program had reached 207,392 people in Port-au-Prince and 113,313 in other areas.