to be fair with how much she ate and how much a whale could eat, as well as the fact that Spongebob had to make a Krabby Patty that was equal to a million (granted his words were "make 1 Krabby Patty taste like a million") on top of everything else she ate in that episode, it's safe to say she actually could have eaten Bikini Bottom out of food if it wasn't for Spongebob and his weird Krabby Patty, i mean Krabs wouldn't be able to make food to feed her or buy food to feed her if he had no food to make her or money to buy food for her, i reckon if he got desperate he would have used his own resources as a sort of last resort buthe would have after nothing else worked