One of the sandwiches sold at posh bakery chain Gail’s contains as much salt as nearly five McDonald’s cheeseburgers, campaigners have found.

The team at Action on Salt & Sugar (AoSS), based at Queen Mary University of London, studied 546 sandwiches, wraps, rolls and baguettes to find out how healthy they were. Adults are recommended to eat no more than 6g of salt per day, and for a child aged ten, it’s 5g – yet the smoked chicken Caesar club sandwich from Gail’s contains 6.88g of salt.

Sarnies from Paul’s and Pret A Manger were also highlighted in the research, which found that overall, more than a tenth of high street sandwiches are exceeding the government’s salt targets. AoSS said it’s “unacceptable” that one sandwich can exceed an adult’s daily limit, and called on the government to do more.

Dell Stanford, from the British Heart Foundation, told the BBC that people shouldn’t be “put off from enjoying a shop-bought sandwich occasionally”, but it’s a good idea to check the packaging and pick ones that are low in salt and saturated fat, and high in fibre.

The World Health Organization says high salt intake is a massive global threat. Last week, it updated its SHAKE The Salt Habit guide, which gives countries step-by-step advice on lowering people’s salt intake.