Grocery inflation has risen for the first time since March 2023, according to closely watched industry data.
Prices in food shops rose by 1.8% in the four weeks to 4 August, research by Kantar Worldpanel found.
It follows 17 consecutive months of easing inflation in the sector, including during the previous month when the rate dropped to 1.6%.
Vitamins, supplements, drinks and chocolate were among the goods that went up fastest in price.
The research, based on the purchasing habits of 30,000 UK households, also found a surge in spending on drinks and snacks during the Euros football tournament and the Olympic Games.
Sales of wine rose by 35%, while nuts increased by 60% and crisps went up by 10% on the Friday of the opening ceremony in Paris, compared with the previous week.
On the day of the Euros final between England and Spain, fans splashed out around £10m in shops on beer alone – the most spent on a Sunday in more than three years, according to the research.
Kantar’s head of retail and consumer insight Fraser McKevitt said grocery inflation was now at a historically normal level, despite the rise.
He said: “Having reached its lowest rate in almost three years in July, August saw inflation nudge up again slightly.
“While this is noticeable following 17 straight months of falling rates, it actually marks a return to the average levels seen in the five years before the start of the cost of living crisis.”
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Warmer weather in recent weeks also helped boost barbecue favourites such as burgers, with sales leaping 32% year-on-year. The amount spent on ice cream also shot up by 23%.
However, amid a suspected summer COVID wave, sales of cough lozenges soared by 28%.
Overall, researchers said there was a mixed picture of price rises when it came to different items on sale.
Kantar said kitchen towels were 7% cheaper than they were last year, with the cost of baked beans also falling by 5%. Bottled colas and dog food prices also dropped.
Mr McKevitt added: “With this kind of pricing spread, shoppers will find that the type of product they’re putting in their baskets will really dictate how much they pay.
“They’re continuing to take advantage of the wide range of promotions being offered by the grocers to help keep the price of shopping down. Spending on deals rose by 15%, while sales of products at their usual price saw no increase.”
Total take-home grocery sales increased by 3.8% during the four-week period.
The official rate of inflation fell to the Bank of England’s target of 2% – for the first time in nearly three years – in May.
It held steady at the same rate in June, helping to pave the way for the Bank to cut interest rates by a quarter percentage point to 5% earlier this month.
The Office for National Statistics will publish its latest inflation figures, covering the month of July, on Wednesday.
The data is likely to feed into the Bank’s decision next month on whether to cut interest rates again.
Financial markets have priced expectations that a reduction is more likely to happen in November rather than September.