A meal of a hotdog with mustard, a burger with cheese and barbecue sauce, a piece of marinated meat, a helping of coleslaw and potato salad and plain crisps with dips can add up to 12.11g of salt, Consensus Action on Salt and Health (Cash) said.
The recommended daily maximum for an adult is 6g a day.
Cash tested 603 barbecue food products including burgers, sausages, crisps, salads and dips from seven supermarkets and brands.
The meal with the lowest amount of salt contained just 2.75g, revealing a significant difference in salt content across similar-looking products, Cash said.
A shopping basket of barbecue items from each of the supermarkets could easily exceed 6g of salt, the study found.