Bakery bread from supermarkets, tested for salt content by the consumer magazine Which?, fell within the ’amber’ range - neither high nor low - under the Food Standards Agency’s traffic-light system for food labelling.

The survey, published this month, showed that Asda’s Granary tin had the least salt, with 0.5g of salt to 100g of bread. The saltiest loaves were Morrisons’ Granary and white sandwich, Sainsbury’s white sandwich and Tesco’s Granary, all averaging 1.1g per 100g of bread.

Which? found that prepac- kaged bread had on average a slightly higher salt content than in-store bakery bread, while brown bread was "practically as salty as white bread".