Take-home grocery sales experienced the fastest rate of growth in 15 years over the past 12 weeks, jumping by a quarter, according to new data from Kantar.
But the boost in take-home purchases was offset somewhat by reduced outlays by consumers on on-the-go meals, drinks and snacks.
"The jump in grocery sales over the most recent three-months in large part reflects the fact that it includes both the pre-lockdown surge in shopper spend and the eight weeks of stay-at-home advice from Government, bringing almost all meals into the home," said Emer Healy, retail analyst at Kantar.
"While the growth of take-home grocery sales is strong, the overall picture for some supermarkets will be less positive as these gains are offset by falling spend on on-the-go meals, drinks and snacks."
Online sales of groceries also leapt, rising 76% compared to the same period a year ago.
"Demand for online groceries has soared over the past few months and 15% of Irish households received at least one online delivery over the latest 12 weeks – a significant increase from 9% last year," said Emer Healy.
"This sudden surge in demand meant that the retailers had to act quickly to increase their online capacity, and have been rightly praised for extending their services to those who need them most."
"That includes reaching groups who are more vulnerable in the current crisis, with an additional 26,000 retired households ordering an online delivery over the 12 weeks to 17 May and over 65s spending an extra €8.9 million online."
With sunny weather dominating over the period and the pubs still shut, sales of alcohol spiked over the month to May 17, jumping 93%.
An additional €3.8 million was spent on sausages and burgers, as consumers fired up their barbecues, while ice cream sales were worth an extra €5.9 million during the period.
Other product categories which experienced large sales increases include haircare products and hair colourants which were up 25% and 73% respectively as people were forced to look after their hair from home.
On the Friday before the May bank holiday weekend began alone, overall sales reached €52.8m.
Patterns of consumer behaviour driven by the Covid-19 restrictions are now apparent in the data, according to Kantar.
"As lockdown continues, households with more mouths to feed at home have made their way through supplies and are now starting to top up depleted store cupboards," said Ms Healy.
"In accordance with Government guidelines, we've seen shoppers limiting their time spent out of home by making fewer, larger trips at local stores, visiting grocers two fewer times over the past 12 weeks than they did in this period last year. Families with children under 16 pushed up their spend by 30% on average."
SuperValu has benefited the most from the boom in sales, claiming the title for the fastest growing retailer over the period as a result of a 32.7% increase in sales and grabbing the largest share of the market overall.
It was followed by Tesco, where sales grew by 23.7% over the month, to leave it with 21.8% of the market.
Overall grocery inflation stood at 2.3% at the end of the three months ending May 17.