The beers, wines and spirits category posted sales of £921.1 million in the two weeks to December 26, up 3.6% year on year.
Sales for the Christmas week itself were particularly strong, up 11.5% on the same period last year, outperforming overall supermarket fmcg sales, which grew 7.4% to £3.1 billion.
Christmas spend continues to come later each year, with sales down 1.6% in the first two weeks of December, only to recover in the two weeks to December 26 and end up 1.1% ahead on 2014.
The uplift in food sales in the back half of the month was driven by cakes and puddings and confectionary.
Sales of Christmas cakes and puddings were up 6.3% in the second fortnight, with Christmas confectionery sales were up 19% to £119.8 million for the Christmas week.
Martin Wood, head of strategic insight, retail solutions and innovation at IRI, said: “There was an extra peak shopping day in Christmas week 2015 compared with last year which helped push up the final week’s sales figures, but the level of growth does provide some good news for supermarkets.
“It shows people are feeling better off at last as wages rise and fuel prices come down, and also that shoppers have not completely abandoned mainstream retailers for the discounters.
“Competition with discounters has driven down prices, however, keeping value and revenues down even when volumes are up.
“The increase in sales of Christmas cakes, puddings and confectionery could be due to the ‘Bake-off effect’ giving people a taste for sweet things once again.
“They want to feature high quality cakes and desserts as centre-pieces of their Christmas meal or party spread, but don’t have time to create these themselves.”