The Irish Supreme court has ruled that the bread served at Subway – a US sandwich food chain with branches in more than 100 countries – cannot be defined as bread.

Under Ireland’s Value-Added Tax Act of 1972 it cannot even be defined as a staple food, according to the Irish Independent, because it contains too much sugar.

The ruling came after an appeal brought before the court by Subway franchisee Bookfinders Ltd. The case rested on whether the bread for subway’s sandwiches counts as a staple food and therefore is VAT-exempt.

The bread’s sugar content – five times the qualifying limit under the act – means that it falls outside of the legal definition of a staple food. The ruling included white and wholegrain bread. The definition serves to differentiate bread from other baked goods.

“The argument depends on the acceptance of the prior contention that the Subway heated sandwich contains ‘bread’ as defined, and therefore can be said to be food for the purposes of the Second Schedule rather than confectionary. Since that argument has been rejected, this subsidiary argument must fail,” the court ruled. The appeal was dismissed.

Subway did not immediately respond to a request from the Guardian for comment.

The ruling is not the first slice of controversy for the brand. In 2014, Subway decided to start removing the flour whitening agent azodicarbonamide from its baked goods after a petition circulated online. The ingredient is commonly used in the manufacture of yoga mats and carpet underlay and has been banned by the European Union and Australia from use in food products.