Sainsbury’s has become the first supermarket chain to end multi-buy promotions in a bid to provide “fair prices” for shoppers.

It comes in the wake of new research by the government-backed Money Advice Service, which reveals that 76% of shoppers regularly spend 21% more than they mean to on a food shop because they are enticed by supermarket deals – parting with an extra £11.14 on average per shop, equivalent to £1,300 a year.

Sainsbury’s commitment extends across its full range of branded and own-brand soft drinks, confectionery, biscuits and crisps. It had already begun phasing out multi-buys on dairy, canned and packaged goods, meat, fish and poultry last year.

The Money Advice Service research criticised the way in which supermarket deals were being displayed, claiming that they made it difficult for shoppers to work out if they were getting a good deal.

This was backed by research which found that only 2% of 2,000 shoppers successfully selected the best value options when presented with four sets of offers commonly found in the supermarkets.

John Penberthy-Smith, customer director for the Money Advice Service, said: “Often deals can be difficult to understand and compare with other prices. Then there’s waste – even if the offers are cheaper, bigger packets or 50% extra are not always good value for money if we end up chucking most of it away.”

Sainsbury’s food commercial director, Paul Mills-Hicks, said: “Customer shopping habits have changed significantly in recent years, with people shopping more frequently – often seeking to buy what they need at that moment in time. By replacing multi-buy promotions with lower regular prices, we are making it easier for customers to buy the products they need, in the quantities they need, without having to buy multiple items to enjoy great value.”

The announcement comes as the government’s Competition and Markets Authority prepares to issue new pricing rules for retailers to ensure that shoppers are not misled.