Biscuits are filled with hidden salt, according to the latest research by campaign group Consensus Action on Salt and Health (CASH).

In a report out this week, it noted that more than 110 biscuits analysed were as salty, or saltier than Butterkist Salted Popcorn, which contains 0.9g of salt per 100g.

The survey looked at the sodium and salt content per 100g, and per biscuit, of 479 sweet biscuit products from six leading supermarkets (Asda, The Co-operative, Morrisons, Sainsbury’s, Tesco and Waitrose), including supermarket own-label and branded products.

Nearly 90% of biscuits sampled received an amber traffic light warning for salt, with 90% showing a red light for sugar content, said CASH, which is calling on the food industry to reduce salt in biscuits.

Biscuits and other products, including buns, cakes, pies, puddings, and pastries contribute towards 4% of the average daily sodium intakes of adults aged 19-64, 6% of children aged 4-10, and 7% of 65+ year-olds’, it claimed.

According to data from the UK’s National Diet and Nutrition Survey 2011, 60% of 19-64 year olds regularly eat biscuits, with children are eating just as many - if not more – biscuits than adults.

Sonia Pombo, nutritionist, CASH: "Many people will be very surprised to hear that so much salt is added to sweet biscuits. This is in the form of either added salt (sodium chloride) or sodium bicarbonate. Both of these are largely unnecessary in biscuits. Even if bicarbonate is required, potassium bicarbonate or calcium bicarbonate can be used instead."