Subway baguettes are now classed as cakes because they are so sugary, amid a new Channel 5 documentary about the sandwich chain.

The popular high street sandwich chain is the subject of a new documentary exploring what goes into Subway’s bread.

What goes into Subway bread?

Speaking in the new documentary In Subway: How Do They Really Do it, analyst Duncan Campbell said: “When we look at the sugars, the Subway roll had 5.5g for each 100g and the one from the local baker 2.4g, so twice as much sugar for Subway.

“They’ve both got similar levels of the sugars which is coming out the bread flour in the proving process prior to baking.

“But then in the Subway roll we find sucrose and some glucose as well, so both of those sugars have been added into the product before baking to make the product sweeter.”

Subway bread not bread, Irish court rules

A spokesperson for Subway, which has restaurants in more than 100 countries, said: “Subway’s bread is, of course, bread.”

However last year in Ireland, a judge found the sugar content of Subway sandwiches exceeds stipulated limit and they should be classified as confectionery.

The Supreme Court said: “In this case, there is no dispute that the bread supplied by Subway in its heated sandwiches has a sugar content of 10% of the weight of the flour included in the dough.”

In the UK Subway baguettes are still classed as bread, just with a high sugar content.

In Subway: How Do They Really Do it will air on Channel 5 on Wednesday night at 8pm.