Mimicking vegetarian celebrities or turned off eating meat by films including Chicken Run and Babe, or by news about mad cow disease, an estimated million schoolchildren are among the growing number of US vegetarians. Many complain that school meal programmes don’t serve their needs.

Over the past five years, most schools have begun serving a vegetarian main course, according to the American School Food Service Association.

The national government subsidises student meals by buying surplus meat from farmers and making it available to schools for nearly nothing, so it is more expensive to provide meatless meals. In one Californian school system, for example, it costs 60 per cent more to prepare a veggie burger than a hamburger.

Jon Marcus