The boss of Sainsbury's has said sales were lower during the Christmas period because fewer people bought toys.
Mike Coupe told the BBC that toy sales had fallen by 20% across the market in the last two years.
"The challenge was in a couple of categories, particularly gaming and toys," he said, adding that there were no major releases to boost sales in the run-up to Christmas.
The supermarket's like-for-like sales fell 0.7% in the 15 weeks to 4 January.
While grocery sales actually increased by 0.4%, poor sales in the division that includes Argos, which is owned by Sainsbury's, weighed on the company's overall performance.
Nevertheless, Mr Coupe said the company had delivered a "real sense of momentum".
Clothing sales grew by 5%, which Mr Coupe said was helped by colder weather in the weeks before Christmas.
"Womenswear was particularly popular, including a sell-out range of novelty Christmas jumpers," Sainsbury's said.
"These results show a mixed picture for the retailer," said Richard Lim, who runs analyst firm Retail Economics.
"On the one hand, the food business held up relatively well in an extremely tough market," he said.
"On the other, Argos appears to have had a much tougher time delivering an uncomfortable decline in sales over the festive period."
Data released by two research firms, Nielsen and Kantar, on Tuesday suggested that Sainsbury's was the least worst performer among the so-called "big four" supermarkets over the all-important Christmas period.
Morrisons reported a 1.7% drop in like-for-like sales, excluding fuel, for the 22 weeks to 5 January.
The company said: "Throughout the period, trading conditions remained challenging and the customer uncertainty of the last year was sustained."