According to a study by magazine Which?, readymade sandwiches contain large amounts of salt, fat and sugar and due to a lack of nutritional information on the sandwiches consumers are eating them presuming them to be healthy. Which? examined nutritional contents and found a Subway, six inch Meatball Marinara contained 4.7 grams of salt which is the same amount that is found in 11.75 regular packets of 25 gms of Walker's Ready Salted crisps.
Out of the 14 popular chicken salad sandwiches the two with the highest calories and fat were Sainsbury's Taste the Difference Butter Roasted Chicken Salad and Pret a Manger's Herb Chicken and Rocket. Pret's Herb Chicken and Rocket sandwich contained 23g of fat, which is similar to a Big Mac.
 Although the saturated fat level was lower than in the burger, it contained the same amount of salt, 2.1g. The Sainsbury's Taste the Difference Butter Roasted Chicken Salad sandwich contains 495 calories as compared to a Big Mac which has 490. The research found that Asda's Vintage Cheddar Ploughman's sandwich, without mayonnaise, has 15.2g of saturated fat which was about 50 % more than a Big Mac which has 24g of fat in total, including 10g of saturated fat. A Wensleydale and Carrot Chutney sandwich from Marks & Spencer was found to contain 25.5g of sugar which translated to more than five teaspoons.
 Martyn Hocking, editor of Which?, said: 'A sandwich might seem like a pretty healthy option, but there can be shocking amounts of salt, sugar and fat in some of them and you'd have no idea if they're not labeled." The saturated fat in the sandwich takes up more than 75 per cent of a woman's recommended daily limit while 2.1 1g of salt is around one third of the recommended daily maximum for an adult of 6g.
The magazine is campaigning for nutritional information to be given on all sandwiches at point of sale. Hocking said, "We're pleased to see that some coffee shops and sandwich chains have signed up to the Food Standards Agency's pilot scheme to provide calorie information when eating out, but we think all food outlets should provide this information as a matter of course." The Food Standards Agency said it is putting pressure on the food industry to cut the levels it uses. A spokesman for Subway said that by June all its products would have
15 % less salt on average and it began giving out nutritional details in shops at the end of last year. Sainsbury's, Asda and M&S all said they provided nutritional information on their sandwiches.

Defending its Vintage Cheddar Ploughman's sandwich Asda said it is part of its Go Large range, so 'it's a big sandwich for a substantial meal'.

The British Sandwich Association said £5.5billion a year is spent on commercially made sandwiches. 'The major chains provide nutrition information to those consumers who want to know,' it said.

'The industry has made huge strides in reducing salt levels, for example, by changing to ingredients with lower levels.'