Takeaway and branded retail pizzas have been criticised for high salt levels, with some containing more than the recommended 6g of salt to be eaten per day, scientific research group Action on Salt has highlighted.

From its analysis of 1,387 different pizzas, available in shops, supermarkets, as a takeaway/delivery and in restaurants, it found that half of the pizzas contained a full day’s recommended salt allowance, The Guardian has reported.

One pizza in Domino’s range contained 21.4g of salt – the equivalent of more than three days’ worth of salt, as recommended by the Scientific Advisory Committee on Nutrition (SACN).

Takeaway pizzas contained more than double the amount of salt found in supermarket-bought ones, while two-thirds of pizzas sold in restaurants and takeaways had 6g or more.

Zizzi, Franco Manca and Crosta & Mollica were the retailers and manufacturers with the saltiest pizzas per 100g, while Domino’s, Papa John’s and Caprinos were the worst offenders in the restaurant and takeaway sector, Action on Salt found.

Bella Italia, PizzaExpress and Fireaway were among the restaurant and takeaway operators offering the least salty options, it noted.

Action on Salt said it was clear that the government’s repeated exhortation of the food industry to use less salt had not worked, with some pizzas containing even high levels of salt that in a similar study it undertook in 2014.

Sonia Pombo, a registered nutritionist who is the group’s campaign lead, said: “Despite our reliance on the food industry to provide us with access to better, healthier options, it’s infuriating to see some companies ignoring the overwhelming evidence in support of salt reduction and, worse still, increasing the salt content further.”

Pizza manufacturers doing so “are showing a complete disregard for public health and are making a mockery of our voluntary reformulation programme”, she added.