The spectre of anti-obesity litigation against the food industry returned last night when a US appeals court ruled that McDonald's must face a suit by New York teenagers seeking billions of dollars for allegedly hiding the health risks of Chicken McNuggets.

The plaintiffs, four teenage girls from the Bronx, are seeking to hold the world's biggest hamburger chain responsible for their obesity and health problems. They say McDonald's deceived customers about its products and failed to display nutritional information prominently enough.