New figures from Kantar show that grocery price inflation hit 16.3% in the 12 weeks to 23 January - the highest level seen since the consultants started tracking grocery inflation.
Irish households are now facing an extra €1,159 on their annual shopping bills if they do not change their behaviour to cut costs, Kantar warned.
Today's figures show that grocery sales rose by 5% in the four weeks to 23 January, with price inflation driving value sales rather than volumes.
Kantar noted that average prices per pack increased by 14.6% in January, while volume per trip fell by 13%.
It said that with people keeping a close eye on their purse strings after Christmas, shoppers continued to trade down to supermarkets' own label products, with sales rising 10.4%.
This was well ahead of a 4.7% increase in branded lines.
Sales of premium own label lines reached €152.6m, up €5.7m from last year with €26.7m of that coming from premium own label chilled convenience products in the 12-week period, to register growth of 11.6%.
Meanwhile, value own label lines saw the strongest growth, up 34% year-on-year with shoppers spending €17.9m more on these ranges.
Emer Healy, Senior Retail Analyst at Kantar, said the Irish grocery market is more competitive than ever before, with shoppers looking for the best deals and retailers looking to retain customers.
This is reflected by many supermarkets using their loyalty schemes to help shoppers save, she said.
"According to Kantar's LinkQ data, nearly 38% of shoppers claim to always use a money saving voucher. As a result, the amount bought on promotion has fallen to 27.7%, the lowest level for five years, exaggerating the usual post-Christmas drop off in deals," she added.
Today's figures show that many consumers here kicked off 2023 with good intentions, making health a priority.
Shoppers spent an additional €848,000 on vitamins and mineral supplements, while "Veganuary" saw sales of meat-free alternatives grow by 4%, with shoppers spending an additional €102,000 on tofu.
"Dry January" also saw sales of non-alcoholic beverages grow 4.6%, with 5% of Irish households purchasing a non-alcoholic beverage during January.
Meanwhile, online sales remained strong during January, up 5.6% on an annual basis with shoppers spending an additional €8.5m in online channels.
An influx of new shoppers boosted online sales, with nearly one in five Irish households now purchasing online, Kantar noted.
Today's figures show that Dunnes Stores held the highest share amongst all retailers at 23.7% with growth of 10.3% year-on-year in the period under review.
Kantar said this growth stemmed from an influx of new shoppers in-store, while shoppers returning more often contributed an additional €24.9m to their overall performance.
Tesco was close behind with 23.1% market share and growth of 9.8% year-on-year. Tesco also had the strongest frequency growth amongst all retailers, up 10% year-on-year.
SuperValu holds 20.9% of the market amid 0.9% growth.
Among the Irish grocery retailers, SuperValu shoppers made the most trips in-store with 20.8 trips on average, up 9.2% year-on-year.
Lidl had a 12.2% market share and 9.9% growth year-on-year. New shoppers and more frequent trips contributed an additional €25.5m to its overall performance.
Meanwhile, Aldi held 11.6% of market share and 6.8% growth year-on-year, with new shoppers and more frequent trips contributing an additional €10.8m to its overall performance.