Market researcher Kantar said prices are rising fastest in markets such as milk, eggs and margarine.
It said UK households now face an additional £811 ($978) on their annual shopping bills if they don't change their behaviour to cut costs.
"This February marks a full year since monthly grocery inflation climbed above 4%. This is having a big impact on people’s lives," Fraser McKevitt, head of retail and consumer insight at Kantar, said.
He said its research found that rising grocery prices are the second most important financial issue for the public behind energy costs. Also a quarter of people say they're struggling financially, versus one in five this time last year.
After a tough 2022, British consumers are facing a further squeeze on their finances this year as the government cuts back support on household energy bills and mortgage rates rise.
Consumer Price Inflation
However, official data published this month did show overall UK consumer price inflation fell to 10.1% in January, the lowest reading since September, while confidence data from market research firm GfK last week showed consumers had turned more upbeat about their personal finances.
Kantar said that sales of own-label products were up by 13.2% in February, well ahead of growth in branded products, which are generally more expensive, of 4.6%.
Kantar said UK grocery sales increased 8.1% over the 12 weeks to 19 February, masking a drop in volumes when accounting for inflation.