Many meals in fast-food restaurants contain "shockingly" high levels of salt, with Pizza Hut the worst offender, according to a report by campaigners.

Cash (Consensus Action on Salt and Health) said some Pizza Hut pizzas contained more than twice the daily recommended amount of salt for an adult. In other cases, family meals could give a child more than four times the daily recommended salt amount.

Cash surveyed 346 food and drink items from Burger King, KFC, McDonald's and Pizza Hut. McDonald's performed particularly well, with no individual products or meals exceeding the 6g a day maximum for adults. However, very salty meals were found at KFC, Burger King and, particularly, at Pizza Hut. Its "Pizza Plus meal for four" contained an average of 12.3g per portion - double an adult's allowance and four times a six-year-old's daily limit. At KFC, a deluxe box shared between four could contain 5.2g of salt per person.

Pizza Hut said the report contained many inaccuracies but failed to list them. A spokesperson said: "Every sensible parent knows Pizza Hut is an enjoyable treat. We have significantly reduced the salt levels in our products."

Cash's findings chime with a warning by the Food Standards Agency that fast food has left many adults with raised salt levels. Excess salt can cause heart disease and stroke, and is estimated to kill thousands of Britons every year.