Which? found the price of 265 groceries soared by more than a fifth at the same time as the availability of supermarket discounts and budget ranges – upon which consumers are increasingly relying – fell.
The watchdog analysed the prices of more than 21,000 groceries over two years, comparing their average prices at eight major supermarkets between the start of December last year and the end of February with the same period two years previously.
Items included Kellogg’s Crunchy Nut Corn Flakes Cereal 500g, which increased by 21.4 per cent at Tesco, Asda’s 250g Own Label Closed Cup Mushrooms, up 21.4 per cent, and Cathedral City Extra Mature Cheddar 350g, which rose by 21.1 per cent at Ocado.
Across 20 categories of groceries, fizzy drinks saw the biggest average price rise at 5.9 per cent, followed by butters and spreads (4.9 per cent), energy drinks (4.8 per cent) and milk (4.6 per cent).
Groceries with the lowest inflation included chocolate (1.4 per cent), fresh fruit (1.6 per cent), biscuits (1.8 per cent) and vegetables (1.9 per cent).
The study also found that across different supermarkets there have been fewer discounts, limited availability of own-label budget ranges and products decreasing in size but remaining the same price over the same period.
The number of promotions fell across every one of the 20 categories the watchdog studied, including the number of discounts on bottled water down 14.7 per cent and on vegetables down 11 per cent.
Meanwhile, the size of savings in promotions that did still happen were also cut in three quarters of the categories. This was most pronounced for butters and spreads, where the size of savings fell by 3.6 per cent over the two years, followed by vegetables (3.5 per cent) and crisps (2.9 per cent).
Examples of ‘shrinkflation’ – reducing the size of product while maintaining the original price – included Nescafé Azera Americano decaffeinated instant coffee shrinking from 100g to 90g and Walkers Classic Variety crisps dropping from 24 bags in a multipack to 22 bags.
Which?’s investigation also found own-brand budget ranges, which have seen the lowest level of inflation at just 0.2 per cent compared with 3.2 per cent for own-label premium ranges, have become less available.
Budget own-brand items were unavailable on three times as many days during the most recent three-month period than two years previously, according to the study.
Sue Davies, Which? head of food policy and consumer rights, said: “Our research reveals that eye-watering price rises are being exacerbated by practices like shrinkflation and limited availability of all-important budget ranges – and these factors are combining to put huge pressure on household shopping budgets.
“During an unrelenting cost-of-living crisis, consumers should be able to easily choose the best value product for them without worrying about shrinkflation or whether their local store stocks budget ranges.”
A Tesco spokesman said: “We are committed to providing great value for our customers, whether it’s promising ‘Low Everyday Prices’ on 1,600 staples, price matching around 650 basics to Aldi prices, or offering exclusive deals and rewards through thousands of Clubcard prices.”