In the 12 weeks to 4 September, take-home grocery sales increased by 3.8%, Kantar said, the third month in a row that the sector's sales have grown, following more than a year of year-on-year declines.
According to Kantar, the current grocery inflation rate means that the average annual grocery bill will go from £4,610 (€5,320) to £5,181 (€5,979), unless shoppers change their shopping habits.
It noted that the price of milk, butter and dog food are rising particularly quickly, at 31%, 25% and 29% respectively.
“In what is a fiercely competitive sector, supermarkets are reacting to make sure they’re seen to acknowledge the challenges consumers are facing and offer best value, in particular by expanding their own-label ranges," commented Fraser McKevitt, head of retail and consumer insight at Kantar.
"Their efforts seem to be well received by consumers, with sales of the very cheapest value own-label products up by 33% this period versus a year ago and nearly one in four baskets containing one of these lines."
Private label's share of the UK grocery market now stands at 51.1%, according to Kantar.
A New Member Of The 'Big Four'
In terms of the best-performing supermarkets during the period, Aldi (9.3%) has jumped ahead of Morrisons (9.1%) to become the UK's fourth-biggest retailer for the first time. The discounter saw sales up 18.7% compared to the same period last year.
Market leader Tesco (26.9%) saw its sales up 1.9% compared to the same period last year, with Sainsbury's (14.6%) up 1.5% and Asda (14.1%) up 2.2%.