Total retail sales in the UK grew by 4.2% last month, according to data from the British Retail Consortium (BRC).
Sales for the four weeks from 1 to 28 January were below the three-month average growth of 5.2%, but above the 12-month average growth of 2.5%.
Like-for-like (LFL) retail sales in the UK rose by 3.9% in the month, compared with an 11.9% growth in the same period of last year.
The data also show that food sales grew by 8.0% and 7.9% on a total and LFL basis, respectively, in the three months to January.
Sales in the UK’s non-food sector increased by 2.9% on a total basis and 2.5% on an LFL basis in these three months.
Non-food sales in stores increased by 7.2% on a total basis in this period and were up by 6.5% on an LFL basis from January last year.
At the same time, online non-food sales fell by 3.6% in the month, having declined by 24.2% last January.
BRC chief executive Helen Dickinson said: “As Christmas cheer subsided, retailers felt the January blues as sales growth slowed.
“Many retailers discounted heavily to entice consumer spend, and while there were bargains to be had in the January sales, retailers continue to be hit by lower margins and falling volumes.
“Own-brand ranges remain popular across food and non-food products, and big-ticket items are seeing customers trade down.”
Last month, the BRC predicted a rise of 2.3-3.5% in retail sales for this year.
Dickinson added: “The coming months will continue to be challenging for retailers and their customers.
“Consumer confidence remains stubbornly low and looming rises in household bills and mortgages mean discretionary spending will remain weak.
“With ongoing cost pressures and labour shortages, increases in sales don’t convert into increases in profits or cash.”