Rising inflation sharply pushed up household food costs in September adding £643 to the average annual bill, according to new data.
A growing number of Britons are also switching to cheaper imperfect products and own-label goods as a result of added financial pressures, according to research company Kantar on Tuesday.
Grocery inflation rose to 13.9 per cent last month, its highest level since records began in 2008, the Kantar study showed.
Official figures showed that in August food and non-alcoholic inflation rose to 13.1 per cent, up from 12.6 per cent in July and the highest since the Office for National Statistics began its records in 1988.
UK inflation data for September will be released next week. Benjamin Nabarro, Citi chief UK economist, forecasts headline inflation to have risen to 10.2 in September, up from 9.9 in August.
The fresh data comes as the IMF severely downgraded the UK economic outlook on Tuesday.
The IMF forecast that the economy will largely stagnate next year on the back of higher inflation and raised borrowing costs after further monetary tightening by the Bank of England.
Borrowing costs shot up after the government announced its tax-cutting “mini” Budget on September 23.
Nabarro is more pessimistic than the IMF about the UK outlook and forecast that the economy will shrink in 2023 and in 2024, largely driven by a contraction in household spending.
According to the Kantar data, consumers are already tightening their budgets as they face near-record price pressures for a generation.
The research showed that the average household can expect their annual grocery bill to jump to £643, or £5,265. At a basket level, this amounts to an extra £3.04 on the typical food shop, which last year stood at about £21.89.
Fraser McKevitt, head of retail and consumer insight at Kantar, said that the data show how the cost of living crisis “is still hitting people hard”.
Shoppers are buying imperfect produce to help manage price rises, Kantar found, as sales of ranges like “Tesco Perfectly Imperfect” and “Morrisons Naturally Wonky” rose by an annual rate of 38 per cent.
Britons are also switching to supermarkets that offer cheaper items. Asda brought an additional 417,000 customers through its doors in the past three months. Meanwhile, affordable brands Aldi and Lidl reported a strong growth in sales.
This contrasted with a contraction in sales for Morrisons and Waitrose, which offer higher-end products.
Kantar bases its research on a year-on-year comparison of more than 75,000 products.
The appetite for own-label goods has also gone up as consumers move away from more expensive products.
Own-label sales increased by an annual rate of 8.1 per cent in September, while branded items declined by 0.7 per cent, Kantar reported.
McKevitt said that Britons were “pretty savvy at seeking out best value and retailers are expanding their ranges to help them do this”.