The cost of more than 200 grocery items has risen by more than 20 per cent in the last two years, a new study has found.
The prices of 265 products rose by at least a fifth during the same time period that the availability of supermarket discounts and budget ranges decreased, according to research by Which?.
The watchdog found that the cost of Kellogg’s Crunchy Nut Corn Flakes Cereal (500g) at Tesco and a pack of Asda’s own label Closed Cup Mushrooms (250g) both rose by 21.4 per cent.
Additionally, Cathedral City Extra Mature Cheddar, 350g, rose by 21.1 per cent at Ocado.
A substantial increase was also seen in fizzy drinks, the cost of which rose by an average of 5.9 per cent, and butters and spreads, which rose by 4.9 per cent.
The price of energy drinks increased by 4.8 per cent and milk went up by 4.6 per cent.
Groceries least affected by inflation included chocolate (1.4 per cent), fresh fruit (1.6 per cent), biscuits (1.8 per cent) and vegetables (1.9 per cent).
Which? found that there have been fewer discounts across different supermarkets, as well as limited availability of own-label budget ranges.
The number of special promotions fell across all 20 categories of groceries that the watchdog studied.
The biggest decrease was seen in discounts on bottled water, down 14.7 per cent, and on vegetables, down 11 per cent.
Which? also observed that some products have decreased in size. The phenomenon, known as “shrinkflation”, sees brands reduce the size of their products while maintaining the original price.
Examples of this include Nescafe 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.
While many supermarkets’ own-brand budget ranges have seen the lowest levels of inflation at an average of just 0.2 per cent, the study found that these 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, commented: “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.”
British Retail Consortium director of food and sustainability Andrew Opie said: “Rising inflation is a continued concern for both consumers and retailers. The global price of many food commodities has reached record highs over the last few months, pushing up prices for consumers.
“Other price pressures include increased energy, transport and labour costs, all of which are being exacerbated by the situation in Ukraine.
“Retailers will continue to do all they can to keep prices down and deliver value for their customers by limiting price rises and expanding their value ranges.”
Additional reporting by PA